According to the 2012 census the population of Sri Lanka was 20,359,439, giving a population density of 325/km<sup>2</sup>. The population had grown by 5,512,689 (37.1%) since the 1981 census (the last full census), equivalent to an annual growth rate of 1.1%.
5,131,666 (25.2%) of the population were aged 14 or under whilst 2,525,573 (12.4%) were aged 60 or over, leaving a working age (15–59) population of 12,702,700. The dependency ratio was 60.2%. There were 5,264,282 households, of which 3,986,236 (75.7%) were headed by males and 1,278,046 (24.3%) were headed by females.
Of those aged 15 or over, 7,857,370 (51.6%) were economically active, 4,199,558 (27.6%) did housework, 1,431,105 (9.4%) were students, 914,934 (6.0%) were unable to work and 346,084 (2.3%) were pensioners. 521,938 (6.6%) of the economically active were unemployed.
The overall literacy rate for those aged 10 and over was 95.7% but amongst those living in the estate sector it was only 86.1%. Of the 18,615,577 aged 5 or over, 499,563 (2.7%) had received a higher education qualification, 2,293,841 (12.3%) had passed G.C.E. A/L, 3,159,402 (17.0%) had passed G.C.E. O/L and 700,419 (3.8%) had no formal schooling. The remaining 11,962,352 (64.3%) had left school with no qualifications or were currently at school. In 2015, Sri Lanka's population aged over 60 was 13.9%, by 2030 this will increase to 21% and by 2050 this number will reach 27.4%.
Age groups
{| class="wikitable"
|-
! width="80pt"|Age group
! width="80pt"|Male
! width="80pt"|Female
! width="80pt"|Total
! width="80pt"|%
|-
| align="right" | Total
| align="right" | 9 856 634
| align="right" | 10 502 805
| align="right" | 20 359 439
| align="right" | 100
|-
| align="right" | 0–4
| align="right" | 879 223
| align="right" | 864 639
| align="right" | 1 743 862
| align="right" | 8.57
|-
| align="right" | 5–9
| align="right" | 882 108
| align="right" | 865 644
| align="right" | 1 747 752
| align="right" | 8.58
|-
| align="right" | 10–14
| align="right" | 829 069
| align="right" | 810 983
| align="right" | 1 640 052
| align="right" | 8.06
|-
| align="right" | 15–19
| align="right" | 819 927
| align="right" | 824 322
| align="right" | 1 644 249
| align="right" | 8.08
|-
| align="right" | 20–24
| align="right" | 742 316
| align="right" | 790 567
| align="right" | 1 532 883
| align="right" | 7.53
|-
| align="right" | 25–29
| align="right" | 743 510
| align="right" | 809 338
| align="right" | 1 552 848
| align="right" | 7.63
|-
| align="right" | 30–34
| align="right" | 796 866
| align="right" | 842 549
| align="right" | 1 639 415
| align="right" | 8.05
|-
| align="right" | 35–39
| align="right" | 686 037
| align="right" | 723 040
| align="right" | 1 409 077
| align="right" | 6.92
|-
| align="right" | 40–44
| align="right" | 661 623
| align="right" | 697 586
| align="right" | 1 359 209
| align="right" | 6.68
|-
| align="right" | 45–49
| align="right" | 618 140
| align="right" | 667 690
| align="right" | 1 285 830
| align="right" | 6.32
|-
| align="right" | 50–54
| align="right" | 581 293
| align="right" | 638 167
| align="right" | 1 219 460
| align="right" | 5.99
|-
| align="right" | 55–59
| align="right" | 500 871
| align="right" | 563 358
| align="right" | 1 064 229
| align="right" | 5.23
|-
| align="right" | 60–64
| align="right" | 425 428
| align="right" | 492 482
| align="right" | 917 910
| align="right" | 4.51
|-
| align="right" | 65–69
| align="right" | 283 764
| align="right" | 349 525
| align="right" | 633 289
| align="right" | 3.11
|-
| align="right" | 70–74
| align="right" | 181 846
| align="right" | 230 568
| align="right" | 412 414
| align="right" | 2.03
|-
| align="right" | 75–79
| align="right" | 116 389
| align="right" | 166 797
| align="right" | 283 186
| align="right" | 1.39
|-
| align="right" | 80–84
| align="right" | 64 250
| align="right" | 95 129
| align="right" | 159 379
| align="right" | 0.78
|-
| align="right" | 85–89
| align="right" | 28 293
| align="right" | 45 148
| align="right" | 73 441
| align="right" | 0.36
|-
| align="right" | 90–94
| align="right" | 9 293
| align="right" | 14 965
| align="right" | 24 258
| align="right" | 0.12
|-
| align="right" | 95+
| align="right" | 6 388
| align="right" | 10 308
| align="right" | 16 696
| align="right" | 0.08
|-
! width="50"|Age group
! width="80pt"|Male
! width="80"|Female
! width="80"|Total
! width="50"|Percent
|-
| align="right" | 0–14
| align="right" | 2 590 400
| align="right" | 2 541 266
| align="right" | 5 131 666
| align="right" | 25.21
|-
| align="right" | 15–64
| align="right" | 6 576 011
| align="right" | 7 049 099
| align="right" | 13 625 110
| align="right" | 66.92
|-
| align="right" | 65+
| align="right" | 690 223
| align="right" | 912 440
| align="right" | 1 602 663
| align="right" | 7.87
|-
|}
Vital statistics
UN estimates
{| class="wikitable"
|-
! width="80pt"|Period
! width="80pt"|Live births per year
! width="80pt"|Deaths per year
! width="80pt"|Natural change per year
! width="80pt"|CBR<sup>1</sup>
! width="80pt"|CDR<sup>1</sup>
! width="80pt"|NC<sup>1</sup>
! width="80pt"|TFR<sup>1</sup>
! width="80pt"|IMR<sup>1</sup>
|-
| 1950–1955
| align="right" | 322,000
| align="right" | 171,000
| align="right" | 151,000
| align="right" | 37.4
| align="right" | 19.8
| align="right" | 17.5
| align="right" | 5.80
| align="right" | 103.9
|-
| 1955–1960
| align="right" | 367,000
| align="right" | 143,000
| align="right" | 223,000
| align="right" | 38.6
| align="right" | 15.1
| align="right" | 23.5
| align="right" | 5.80
| align="right" | 86.7
|-
| 1960–1965
| align="right" | 377,000
| align="right" | 128,000
| align="right" | 248,000
| align="right" | 35.5
| align="right" | 12.1
| align="right" | 23.4
| align="right" | 5.20
| align="right" | 77.5
|-
| 1965–1970
| align="right" | 391,000
| align="right" | 116,000
| align="right" | 276,000
| align="right" | 32.9
| align="right" | 9.7
| align="right" | 23.2
| align="right" | 4.70
| align="right" | 69.3
|-
| 1970–1975
| align="right" | 383,000
| align="right" | 103,000
| align="right" | 280,000
| align="right" | 29.1
| align="right" | 7.8
| align="right" | 21.3
| align="right" | 4.00
| align="right" | 55.4
|-
| 1975–1980
| align="right" | 401,000
| align="right" | 99,000
| align="right" | 302,000
| align="right" | 27.8
| align="right" | 6.9
| align="right" | 20.9
| align="right" | 3.61
| align="right" | 38.8
|-
| 1980–1985
| align="right" | 401,000
| align="right" | 96,000
| align="right" | 305,000
| align="right" | 25.6
| align="right" | 6.1
| align="right" | 19.5
| align="right" | 3.19
| align="right" | 30.3
|-
| 1985–1990
| align="right" | 362,000
| align="right" | 110,000
| align="right" | 253,000
| align="right" | 21.6
| align="right" | 6.5
| align="right" | 15.1
| align="right" | 2.64
| align="right" | 24.1
|-
| 1990–1995
| align="right" | 349,000
| align="right" | 119,000
| align="right" | 230,000
| align="right" | 19.6
| align="right" | 6.7
| align="right" | 12.9
| align="right" | 2.39
| align="right" | 22.1
|-
| 1995–2000
| align="right" | 329,000
| align="right" | 146,000
| align="right" | 183,000
| align="right" | 17.8
| align="right" | 7.9
| align="right" | 9.9
| align="right" | 2.16
| align="right" | 18.9
|-
| 2000–2005
| align="right" | 360,000
| align="right" | 121,000
| align="right" | 239,000
| align="right" | 18.7
| align="right" | 6.3
| align="right" | 12.4
| align="right" | 2.27
| align="right" | 15.9
|-
| 2005–2010
| align="right" | 386,000
| align="right" | 132,000
| align="right" | 253,000
| align="right" | 19.0
| align="right" | 6.5
| align="right" | 12.5
| align="right" | 2.36
| align="right" | 12.4
|-
| 2010–2015
| align="right" |
| align="right" |
| align="right" |
| align="right" | 16.4
| align="right" | 6.6
| align="right" | 9.8
| align="right" | 2.11
| align="right" |
|-
| 2015–2020
| align="right" |
| align="right" |
| align="right" |
| align="right" | 14.9
| align="right" | 7.1
| align="right" | 7.8
| align="right" | 2.03
| align="right" |
|-
| colspan="9"| <sup>1</sup> <small>CBR = crude birth rate (per 1000); CDR = crude death rate (per 1000); NC = natural change (per 1000); TFR = total fertility rate (number of children per woman); IMR = infant mortality rate per 1000 births</small>
|}
Registered births and deaths
{| class="wikitable sortable sort-under sticky-header-multi" style="text-align:right;"
|-
! width="70"|Year
! width="70"|Population
! width="70"|Live births
! width="70"|Deaths
! width="70"|Natural change
! width="70"|Crude birth rate (per 1000)
! width="70"|Crude death rate (per 1000)
! width="70"|Natural change (per 1000)
! width="70"|Crude migration change (per 1000)
! width="70"|Total Fertility Rate
|-
| align="right" | 1948
| align="right" |
| align="right" | 287,695
| align="right" | 93,711
| align="right" | 193,984
| align="right" | 39.7
| align="right" | 13.0
| align="right" | 26.7
| align="right" |
|-
| align="right" | 1949
| align="right" |
| align="right" | 291,191
| align="right" | 91,889
| align="right" | 199,302
| align="right" | 39.1
| align="right" | 12.4
| align="right" | 26.7
| align="right" |
|-
| align="right" | 1950
| align="right" |
| align="right" | 304,635
| align="right" | 95,142
| align="right" | 209,493
| align="right" | 39.7
| align="right" | 12.6
| align="right" | 27.1
| align="right" |
|-
| align="right" | 1951
| align="right" |
| align="right" | 313,662
| align="right" | 100,072
| align="right" | 213,590
| style="color:blue;"| 39.8
| align="right" | 12.9
| align="right" | 26.9
| align="right" |
|-
| align="right" | 1952
| align="right" |
| align="right" | 313,532
| align="right" | 95,298
| align="right" | 218,234
| align="right" | 38.8
| align="right" | 12.0
| align="right" | 26.8
| align="right" |
|-
| align="right" | 1953
| align="right" |
| align="right" | 321,217
| align="right" | 89,003
| align="right" | 232,214
| align="right" | 38.7
| align="right" | 10.9
| align="right" | 27.8
| align="right" |
|-
| align="right" | 1954
| align="right" |
| align="right" | 303,894
| align="right" | 86,794
| align="right" | 217,100
| align="right" | 35.7
| align="right" | 10.4
| align="right" | 25.3
| align="right" |
|-
| align="right" | 1955
| align="right" |
| align="right" | 325,538
| align="right" | 94,368
| align="right" | 231,170
| align="right" | 37.3
| align="right" | 11.0
| align="right" | 26.3
| align="right" |
|-
| align="right" | 1956
| align="right" |
| align="right" | 325,067
| align="right" | 87,561
| align="right" | 237,506
| align="right" | 36.4
| align="right" | 9.8
| align="right" | 26.6
| align="right" |
|-
| align="right" | 1957
| align="right" |
| align="right" | 334,135
| align="right" | 92,759
| align="right" | 241,376
| align="right" | 36.5
| align="right" | 10.1
| align="right" | 26.4
| align="right" |
|-
| align="right" | 1958
| align="right" |
| align="right" | 335,690
| align="right" | 90,815
| align="right" | 244,875
| align="right" | 35.8
| align="right" | 9.7
| align="right" | 26.1
| align="right" |
|-
| align="right" | 1959
| align="right" |
| align="right" | 356,336
| align="right" | 87,971
| align="right" | 268,365
| align="right" | 37.0
| align="right" | 9.1
| align="right" | 27.9
| align="right" |
|-
| align="right" | 1960
| align="right" |
| align="right" | 361,702
| align="right" | 84,918
| align="right" | 276,784
| align="right" | 36.6
| align="right" | 8.6
| style="color:blue;"| 28.0
| align="right" |
|-
| align="right" | 1961
| align="right" |
| align="right" | 363,677
| style="color:blue;"| 81,653
| align="right" | 282,024
| align="right" | 35.8
| align="right" | 8.0
| align="right" | 27.8
| align="right" |
|-
| align="right" | 1962
| align="right" |
| align="right" | 370,762
| align="right" | 88,928
| align="right" | 281,834
| align="right" | 35.5
| align="right" | 8.5
| align="right" | 27.0
| align="right" |
|-
| align="right" | 1963
| align="right" |
| align="right" | 365,842
| align="right" | 91,673
| align="right" | 274,169
| align="right" | 34.1
| align="right" | 8.5
| align="right" | 25.6
| align="right" |
|-
| align="right" | 1964
| align="right" |
| align="right" | 361,577
| align="right" | 95,618
| align="right" | 265,959
| align="right" | 33.2
| align="right" | 8.8
| align="right" | 24.4
| align="right" |
|-
| align="right" | 1965
| align="right" |
| align="right" | 369,437
| align="right" | 91,728
| align="right" | 277,709
| align="right" | 33.1
| align="right" | 8.8
| align="right" | 24.3
| align="right" |
|-
| align="right" | 1966
| align="right" |
| align="right" | 369,153
| align="right" | 94,419
| align="right" | 274,734
| align="right" | 32.3
| align="right" | 8.3
| align="right" | 24.0
| align="right" |
|-
| align="right" | 1967
| align="right" |
| align="right" | 369,531
| align="right" | 87,877
| align="right" | 281,654
| align="right" | 31.9
| align="right" | 7.5
| align="right" | 24.4
| align="right" |
|-
| align="right" | 1968
| align="right" |
| align="right" | 384,178
| align="right" | 94,903
| align="right" | 289,275
| align="right" | 32.0
| align="right" | 7.9
| align="right" | 24.1
| align="right" |
|-
| align="right" | 1969
| align="right" |
| align="right" | 372,774
| align="right" | 102,356
| align="right" | 270,418
| align="right" | 30.4
| align="right" | 8.1
| align="right" | 22.3
| align="right" |
|-
| align="right" | 1970
| align="right" |
| align="right" | 367,901
| align="right" | 94,129
| align="right" | 273,772
| align="right" | 29.4
| align="right" | 7.5
| align="right" | 21.9
| align="right" |
|-
| align="right" | 1971
| align="right" |
| align="right" | 382,668
| align="right" | 96,328
| align="right" | 286,340
| align="right" | 30.4
| align="right" | 7.7
| align="right" | 22.7
| align="right" |
|-
| align="right" | 1972
| align="right" |
| align="right" | 385,462
| align="right" | 100,080
| align="right" | 285,382
| align="right" | 30.0
| align="right" | 8.1
| align="right" | 21.9
| align="right" |
|-
| align="right" | 1973
| align="right" |
| align="right" | 367,158
| align="right" | 100,678
| align="right" | 266,480
| align="right" | 28.0
| align="right" | 7.7
| align="right" | 20.3
| align="right" |
|-
| align="right" | 1974
| align="right" |
| align="right" | 365,902
| align="right" | 119,518
| align="right" | 246,384
| align="right" | 27.5
| align="right" | 9.0
| align="right" | 18.5
| align="right" |
|-
| align="right" | 1975
| align="right" |
| align="right" | 374,689
| align="right" | 115,108
| align="right" | 259,581
| align="right" | 27.8
| align="right" | 8.5
| align="right" | 19.3
| align="right" |
|-
| align="right" | 1976
| align="right" |
| align="right" | 380,702
| align="right" | 106,506
| align="right" | 274,196
| align="right" | 27.8
| align="right" | 7.8
| align="right" | 20.0
| align="right" |
|-
| align="right" | 1977
| align="right" |
| align="right" | 389,522
| align="right" | 103,284
| align="right" | 286,238
| align="right" | 27.9
| align="right" | 7.4
| align="right" | 20.5
| align="right" |
|-
| align="right" | 1978
| align="right" |
| align="right" | 404,831
| align="right" | 93,971
| align="right" | 310,860
| align="right" | 28.5
| align="right" | 6.6
| align="right" | 21.9
| align="right" |
|-
| align="right" | 1979
| align="right" |
| align="right" | 417,986
| align="right" | 94,244
| align="right" | 323,742
| align="right" | 28.9
| align="right" | 6.5
| align="right" | 22.4
| align="right" |
|-
| align="right" | 1980
| align="right" |
| align="right" | 418,373
| align="right" | 91,020
| align="right" | 327,353
| align="right" | 28.4
| align="right" | 6.2
| align="right" | 22.2
| align="right" |
|-
| align="right" | 1981
| align="right" |
| style="color:blue;"| 423,973
| align="right" | 88,481
| style="color:blue;"| 335,492
| align="right" | 28.2
| align="right" | 5.9
| align="right" | 22.3
| align="right" |
|-
| align="right" | 1982
| align="right" |
| align="right" | 408,895
| align="right" | 92,244
| align="right" | 316,651
| align="right" | 26.9
| align="right" | 6.1
| align="right" | 20.8
| align="right" |
|-
| align="right" | 1983
| align="right" |
| align="right" | 405,122
| align="right" | 95,174
| align="right" | 309,948
| align="right" | 26.3
| align="right" | 6.2
| align="right" | 20.1
| align="right" |
|-
| align="right" | 1984
| align="right" |
| align="right" | 391,064
| align="right" | 100,725
| align="right" | 290,339
| align="right" | 25.1
| align="right" | 6.5
| align="right" | 18.6
| align="right" |
|-
| align="right" | 1985
| align="right" |
| align="right" | 389,599
| align="right" | 98,089
| align="right" | 291,510
| align="right" | 24.6
| align="right" | 6.2
| align="right" | 18.4
| align="right" |
|-
| align="right" | 1986
| align="right" |
| align="right" | 361,735
| align="right" | 96,145
| align="right" | 265,590
| align="right" | 22.4
| align="right" | 6.0
| align="right" | 16.4
| align="right" |
|-
| align="right" | 1987
| align="right" |
| align="right" | 357,723
| align="right" | 97,756
| align="right" | 259,967
| align="right" | 21.8
| align="right" | 6.0
| align="right" | 15.8
| align="right" |
|-
| align="right" | 1988
| align="right" |
| align="right" | 344,179
| align="right" | 95,934
| align="right" | 248,245
| align="right" | 20.7
| align="right" | 5.8
| align="right" | 14.9
| align="right" |
|-
| align="right" | 1989
| align="right" |
| align="right" | 363,343
| align="right" | 105,239
| align="right" | 258,104
| align="right" | 21.6
| align="right" | 6.3
| align="right" | 15.3
| align="right" |
|-
| align="right" | 1990
| align="right" |
| align="right" | 341,223
| align="right" | 97,713
| align="right" | 243,510
| align="right" | 20.8
| align="right" | 6.0
| align="right" | 14.8
| align="right" |
|-
| align="right" | 1991
| align="right" |
| align="right" | 356,593
| align="right" | 95,574
| align="right" | 261,019
| align="right" | 21.7
| align="right" | 5.8
| align="right" | 15.9
| align="right" |
|-
| align="right" | 1992
| align="right" |
| align="right" | 356,842
| align="right" | 98,380
| align="right" | 258,462
| align="right" | 21.5
| align="right" | 5.9
| align="right" | 15.6
| align="right" |
|-
| align="right" | 1993
| align="right" |
| align="right" | 350,707
| align="right" | 96,179
| align="right" | 254,528
| align="right" | 20.8
| style="color:blue;"| 5.7
| align="right" | 15.1
| align="right" |
|-
| align="right" | 1994
| align="right" |
| align="right" | 356,071
| align="right" | 100,394
| align="right" | 255,677
| align="right" | 20.8
| align="right" | 5.9
| align="right" | 14.9
| align="right" |
|-
| align="right" | 1995
| align="right" |
| align="right" | 343,224
| align="right" | 104,707
| align="right" | 238,517
| align="right" | 19.9
| align="right" | 6.0
| align="right" | 13.9
| align="right" |
|-
| align="right" | 1996
| align="right" |
| align="right" | 340,649
| align="right" | 122,161
| align="right" | 218,488
| align="right" | 19.5
| align="right" | 7.0
| align="right" | 12.5
| align="right" |
|-
| align="right" | 1997
| align="right" |
| align="right" | 333,219
| align="right" | 114,591
| align="right" | 218,628
| align="right" | 18.8
| align="right" | 6.4
| align="right" | 12.4
| align="right" |
|-
| align="right" | 1998
| align="right" |
| align="right" | 322,672
| align="right" | 112,653
| align="right" | 210,019
| align="right" | 18.2
| align="right" | 6.2
| align="right" | 12.0
| align="right" |
|-
| align="right" | 1999
| align="right" |
| align="right" | 328,725
| align="right" | 115,330
| align="right" | 213,395
| align="right" | 18.1
| align="right" | 6.3
| align="right" | 11.8
| align="right" |
|-
| align="right" | 2000
| align="right" |
| align="right" | 347,749
| align="right" | 116,200
| align="right" | 231,549
| align="right" | 18.4
| align="right" | 6.1
| align="right" | 12.3
| align="right" |
|-
| align="right" | 2001
| align="right" |
| align="right" | 358,583
| align="right" | 112,858
| align="right" | 245,725
| align="right" | 18.9
| align="right" | 5.9
| align="right" | 13.0
| align="right" |
|-
| align="right" | 2002
| align="right" |
| align="right" | 367,709
| align="right" | 111,863
| align="right" | 255,846
| align="right" | 19.1
| align="right" | 5.8
| align="right" | 13.3
| align="right" |
|-
| align="right" | 2003
| align="right" |
| align="right" | 370,643
| align="right" | 115,495
| align="right" | 255,148
| align="right" | 18.9
| align="right" | 5.9
| align="right" | 13.0
| align="right" |
|-
| align="right" | 2004
| align="right" |
| align="right" | 364,711
| align="right" | 114,915
| align="right" | 249,796
| align="right" | 18.5
| align="right" | 5.8
| align="right" | 12.7
| align="right" |
|-
| align="right" | 2005
| align="right" |
| align="right" | 370,731
| align="right" | 132,097
| align="right" | 238,634
| align="right" | 18.1
| align="right" | 6.5
| align="right" | 11.6
| align="right" |
|-
| align="right" | 2006
| align="right" |
| align="right" | 373,538
| align="right" | 117,467
| align="right" | 256,071
| align="right" | 18.8
| align="right" | 5.9
| align="right" | 12.9
| align="right" |
|-
| align="right" | 2007
| align="right" |
| align="right" | 386,573
| align="right" | 118,992
| align="right" | 267,581
| align="right" | 19.2
| align="right" | 5.9
| align="right" | 13.3
| align="right" |
|-
| align="right" | 2008
| align="right" |
| align="right" | 373,575
| align="right" | 123,814
| align="right" | 249,761
| align="right" | 18.4
| align="right" | 6.1
| align="right" | 12.3
| align="right" |
|-
| align="right" | 2009
| align="right" |
| align="right" | 368,304
| align="right" | 127,776
| align="right" | 240,528
| align="right" | 18.0
| align="right" | 6.2
| align="right" | 11.8
| align="right" |
|-
| align="right" | 2010
| align="right" |
| align="right" | 364,565
| align="right" | 128,603
| align="right" | 235,962
| align="right" | 17.7
| align="right" | 6.2
| align="right" | 11.4
| align="right" |
|-
| align="right" | 2011
| align="right" |
| align="right" | 363,415
| align="right" | 123,261
| align="right" | 240,154
| align="right" | 17.4
| align="right" | 5.9
| align="right" | 11.5
| align="right" |
|-
| align="right" | 2012
| align="right" | 20,425,000
| align="right" | 355,900
| align="right" | 122,063
| align="right" | 233,837
| align="right" | 17.5
| align="right" | 6.0
| align="right" | 11.5
|
| align="right" style="color: blue" |2.252
|-
| align="right" | 2013
| align="right" | 20,585,000
| align="right" | 365,792
| align="right" | 127,124
| align="right" | 238,668
| align="right" | 17.9
| align="right" | 6.2
| align="right" | 11.7
| −3.9
| align="right" style="color: blue" |2.264
|-
| align="right" | 2014
| align="right" | 20,771,000
| align="right" | 349,715
| align="right" | 127,758
| align="right" | 221,957
| align="right" | 16.8
| align="right" | 6.2
| align="right" | 10.6
| −1.6
| align="right" style="color: blue" | 2.148
|-
| align="right" | 2015
| align="right" | 20,970,000
| align="right" | 334,821
| align="right" | 131,634
| align="right" | 203,187
| align="right" | 16.0
| align="right" | 6.3
| align="right" | 9.7
| −0.1
| align="right" | 2.046
|-
| align="right" | 2016
| align="right" | 21,203,000
| align="right" | 331,073
| align="right" | 130,765
| align="right" | 200,308
| align="right" | 15.6
| align="right" | 6.2
| align="right" | 9.4
| 1.7
| align="right" | 1.985
|-
| align="right" | 2017
| align="right" | 21,444,000
| align="right" | 326,052
| align="right" | 139,822
| align="right" | 186,230
| align="right" | 15.2
| align="right" | 6.5
| align="right" | 8.7
| 2.7
| align="right" | 1.944
|-
| align="right" | 2018
| align="right" | 21,670,000
| align="right" | 328,112
| align="right" | 139,498
| align="right" | 188,614
| align="right" | 15.1
| align="right" | 6.4
| align="right" | 8.7
| 1.8
| align="right" | 1.937
|-
| align="right" | 2019
| align="right" | 21,803,000
| align="right" | 319,010
| align="right" | 146,053
| align="right" | 172,957
| align="right" | 14.6
| align="right" | 6.7
| align="right" | 7.9
| −1.8
| align="right" | 1.871
|-
| align="right" | 2020
| align="right" | 21,919,000
| align="right" | 301,706
| align="right" | 132,431
| align="right" | 169,275
| align="right" | 13.8
| align="right" | 6.0
| align="right" | 7.8
| −2.5
| align="right" | 1.756
|-
| align="right" | 2021
| align="right" | 22,156,000
| align="right" | 284,848
| align="right" | 163,936
| align="right" | 120,912
| align="right" | 12.9
| align="right" | 7.4
| align="right" | 5.5
| 5.3
| align="right" | 1.7(e)
|-
| align="right" | 2022
| align="right" style="color: blue" | 22,181,000
| align="right" | 275,321
| align="right" | 179,792
| align="right" | 95,529
| align="right" | 12.4
| align="right" | 8.1
| align="right" | 4.3
| −3.2
| align="right" | 1.65(e)
|-
| align="right" | 2023
| align="right" | 22,037,000
| align="right" | 247,900
| align="right" style="color: red" | 181,239
| align="right" | 66,661
| align="right" | 11.2
| align="right" | 8.2
| align="right" | 3.0
| −9.6
| align="right" | 1.49(e)
|-
| align="right" | 2024
| align="right" | 21,916,000
| align="right" | 220,761
| align="right" | 171,194
| align="right" | 49,567
| align="right" | 10.1
| align="right" | 7.8
| align="right" | 2.3
| −7.8
| align="right" style="color: red" | 1.37(e)
|-
| align="right" | 2025
| align="right" | 21,756,000
| align="right" style="color: red" | 214,570
| align="right" | 172,603
| align="right" style="color: red" | 41,967
| align="right" style="color: red" | 9.9
| align="right" | 7.9
| align="right" style="color: red"| 2.0
| −9.3
| align="right" style="color: red" |
|-
|}
Current vital statistics
{| class="wikitable" style="text-align:center;"
|+
|-
! Period
! Live births
! Deaths
! Natural increase
|-
! January–June 2024
| 109,025
|
| +
|-
! January–June 2025
| 110,652
|
|
|-
! Difference
| +1,627 (+1.5%)
|
| –
|-
! colspan="4" style="text-align: center;" | Source:
|}
Demographic and Health Surveys
Total Fertility Rate (TFR) (Wanted Fertility Rate) and Crude Birth Rate (CBR):
{| class="wikitable"
|-
!rowspan=2 style="width:70pt;"| Year
!colspan=2| total
!colspan=2| urban
!colspan=2| rural
!colspan=2| estate
|-
! style="width:50pt;"| CBR
! style="width:50pt;"| TFR
! style="width:50pt;"| CBR
! style="width:50pt;"| TFR
! style="width:50pt;"| CBR
! style="width:50pt;"| TFR
! style="width:50pt;"| CBR
! style="width:50pt;"| TFR
|-
| 1981–1983
| style="text-align:right;"|
| style="text-align:right;"| 3,1
| style="text-align:right;"|
| style="text-align:right;"| 2,4
| style="text-align:right;"|
| style="text-align:right;"| 3,2
| style="text-align:right;"|
| style="text-align:right;"| 3,4
|-
| 1987
| style="text-align:right;"|
| style="text-align:right;"| 2,8 (2,4)
| style="text-align:right;"|
| style="text-align:right;"| 2,3 (1,9)
| style="text-align:right;"|
| style="text-align:right;"| 2,9 (2,4)
| style="text-align:right;"|
| style="text-align:right;"| 3,4 (3,2)
|-
| 2006–2007
| style="text-align:right;"| 18,7
| style="text-align:right;"| 2,3 (2,1)
| style="text-align:right;"| 18,5
| style="text-align:right;"| 2,2 (2,0)
| style="text-align:right;"| 18,6
| style="text-align:right;"| 2,3 (2,1)
| style="text-align:right;"| 20,0
| style="text-align:right;"| 2,5 (2,1)
|-
| 2024
| style="text-align:right;"|
| style="text-align:right;"| 1.3
| style="text-align:right;"|
| style="text-align:right;"| 1.2
| style="text-align:right;"|
| style="text-align:right;"| 1.3
| style="text-align:right;"|
| style="text-align:right;"| 1.6
|-
|}
Life expectancy
thumb|[[Life expectancy in Sri Lanka since 1901]]
thumb|Life expectancy in Sri Lanka since 1960 by gender
{| class="wikitable" style="text-align:center"
!Period
!Life expectancy in<br />Years
!Period
!Life expectancy in<br />Years
|-
|1950–1955
|54.5
|1985–1990
|68.9
|-
|1955–1960
|58.3
|1990–1995
|70.0
|-
|1960–1965
|60.3
|1995–2000
|69.1
|-
|1965–1970
|62.9
|2000–2005
|73.2
|-
|1970–1975
|65.2
|2005–2010
|74.1
|-
|1975–1980
|67.0
|2010–2015
|74.6
|-
|1980–1985
|69.1
|
|
|}
Ethnicity
thumbnail|left|200px|Majority ethnicity by DS Division according to 2012 census
The Sinhalese make up 74.9% of the population (according to 2012 census) and are concentrated in the densely populated south-west and central parts of the island. Under the pact, India granted citizenship to the remainder, some 200,000 of whom now live in India. Another 75,000 Indian Tamils, who themselves or whose parents once applied for Indian citizenship, now wish to remain in Sri Lanka. The government has stated these Tamils will not be forced to return to India, although they are not technically citizens of Sri Lanka. By the 1990s most Indian Tamils had received Sri Lankan citizenship, and some even were not granted Sri Lankan citizenship until 2003.
Smaller minorities include the Veddas, the indigenous people of Sri Lanka; Malays who descend from Austronesian settlers; the Burghers, who are descendants of European colonists, principally from Portugal, the Netherlands and, the UK; the ethnic Chinese migrants who came to the island in the 18th and 19th centuries; and the Kaffirs, a small population who are descended from Africans.
{| class="wikitable" style="text-align:right; font-size:95%"
|+ Population of Sri Lanka by ethnic group 1881 to 2012
! rowspan=2|Year
! colspan=2|Sinhalese
! colspan=2|Sri Lankan Tamils
! colspan=2|Sri Lankan Moors
! colspan=2|Indian Tamils
! colspan=2|Sri Lankan Malays
! colspan=2|Burghers/<br />Eurasian
! colspan=2|Indian Moors
! colspan=2|Others
! rowspan=2|Total<br />No.
|-
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
! width="60"|No. || width="40"|%
|-
| align=left|1881 Census
| 1,846,600 ||
| 687,200 ||
| 184,500 ||
| colspan=2|
| 8,900 ||
| 17,900 ||
| colspan=2|
| 14,500 ||
| 2,759,700
|-
| align=left|1891 Census
| 2,041,200 ||
| 723,900 ||
| 197,200 ||
| colspan=2|
| 10,100 ||
| 21,200 ||
| colspan=2|
| 14,200 ||
| 3,007,800
|-
| align=left|1901 Census
| 2,330,800 ||
| 951,700 ||
| 228,000 ||
| colspan=2|
| 11,900 ||
| 23,500 ||
| colspan=2|
| 20,000 ||
| 3,566,000
|-
| align=left|1911 Census
| 2,715,500 ||
| 528,000 ||
| 233,900 ||
| 531,000 ||
| 13,000 ||
| 26,700 ||
| 32,700 ||
| 25,600 ||
| 4,106,400
|-
| align=left|1921 Census
| 3,016,200 ||
| 517,300 ||
| 251,900 ||
| 602,700 ||
| 13,400 ||
| 29,400 ||
| 33,000 ||
| 34,600 ||
| 4,498,600
|-
| align=left|1931 Estimate
| 3,473,000 ||
| 598,900 ||
| 289,600 ||
| 818,500 ||
| 16,000 ||
| 32,300 ||
| 36,300 ||
| 41,800 ||
| 5,306,000
|-
| align=left|1946 Census
| 4,620,500 ||
| 733,700 ||
| 373,600 ||
| 780,600 ||
| 22,500 ||
| 41,900 ||
| 35,600 ||
| 48,900 ||
| 6,657,300
|-
| align=left|1953 Census
| 5,616,700 ||
| 884,700 ||
| 464,000 ||
| 974,100 ||
| 25,400 ||
| 46,000 ||
| 47,500 ||
| 39,500 ||
| 8,097,900
|-
| align=left|1963 Census
| 7,512,900 ||
| 1,164,700 ||
| 626,800 ||
| 1,123,000 ||
| 33,400 ||
| 45,900 ||
| 55,400 ||
| 19,900 ||
| 10,582,000
|-
| align=left|1971 Census
| 9,131,241 ||
| 1,423,981 ||
| 855,724 ||
| 1,174,606 ||
| 43,459 ||
| 45,376 ||
| colspan=2|
| 15,510 ||
| 12,689,897
|-
| align=left|1981 Census
| 10,979,561 ||
| 1,886,872 ||
| 1,046,926 ||
| 818,656 ||
| 46,963 ||
| 39,374 ||
| colspan=2|
| 28,398 ||
| 14,846,750
|-
| align=left|2001 Census
| colspan=17|
|-
| align=left|2011 Census
| 15,250,081 ||
| 2,269,266 ||
| 1,892,638 ||
| 839,504 ||
| 44,130 ||
| 38,293 ||
| colspan=2|
| 25,527 ||
| 20,359,439
|-
| align=left|2024 Census
| 16,144,037 ||
| 2,681,627 ||
| 2,283,246 ||
| 600,360 ||
| colspan=6|
| 72,530 ||
| 21,781,800
|}
<gallery perrow="4" heights="170" widths="160" caption="Data from the 2011 census">
Singhalesen 2012.svg|Sinhalese
Sri Lanka-Tamilen 2012.svg|Sri Lankan Tamils
Moors 2012.svg|Sri Lankan Moors
Indische Tamilen 2012.svg|Indian/Malayaga Tamils
</gallery>
Languages
thumbnail|right|150px|A multi-lingual road sign
Sinhala, an Indo-Aryan language, is the first language of Sinhalese people. Unlike Tamil Sinhala language is not found in India and is unique to Sri Lanka.
Tamil, a Dravidian language, is the first language of native Sri Lankan Tamils. Tamil is also the first language of the majority of Sri Lankan Moors and the Indian Tamils – according to the 2012 census 98% of Sri Lankan Moors could speak Tamil but only 59% could speak Sinhala.
English is fluently spoken by approximately 23.8% of the Sri Lanka's population, and widely used for official and commercial purposes.
Malays speak Sri Lanka Malay, a Creole language mixing Sinhala, Tamil and Malay. Many of the Burghers speak Sri Lankan Indo-Portuguese although its use has declined and the majority now speak Sinhala.
Religion
thumbnail|right|200px|Majority religion by DS Division according to 2012 census
According to the 2012 census Buddhists make up 70.2% of the population, Hindus 12.6%, Muslims 9.7% and Christians 7.6%.
{| class="wikitable" style="text-align:right;"
|+Population of Sri Lanka by religion 1881 to 2012
! rowspan=2|Year
! colspan=2|Buddhist
! colspan=2|Hindu
! colspan=2|Muslim
! colspan=2|Christian
! colspan=2|Others
! colspan=2|Total
|-
! width="70"|No. || width="50"|%
! width="70"|No. || width="50"|%
! width="70"|No. || width="50"|%
! width="70"|No. || width="50"|%
! width="70"|No. || width="50"|%
! width="70"|No.
|-
| align=left|1881 Census
| 1,698,100 ||
| 593,600 ||
| 197,800 ||
| 268,000 ||
| 2,300 ||
| 2,759,800
|-
| align=left|1891 Census
| 1,877,000 ||
| 615,900 ||
| 212,000 ||
| 302,100 ||
| 800 ||
| 3,007,800
|-
| align=left|1901 Census
| 2,141,400 ||
| 826,800 ||
| 246,100 ||
| 349,200 ||
| 2,500 ||
| 3,566,000
|-
| align=left|1911 Census
| 2,474,200 ||
| 938,300 ||
| 283,600 ||
| 409,200 ||
| 1,100 ||
| 4,106,400
|-
| align=left|1921 Census
| 2,769,800 ||
| 982,100 ||
| 302,500 ||
| 443,400 ||
| 800 ||
| 4,498,600
|-
| align=left|1931 Estimate
| 3,266,600 ||
| 1,166,900 ||
| 354,200 ||
| 518,100 ||
| 1,100 ||
| 5,306,900
|-
| align=left|1946 Census
| 4,294,900 ||
| 1,320,400 ||
| 436,600 ||
| 603,200 ||
| 2,200 ||
| 6,657,300
|-
| align=left|1953 Census
| 5,209,400 ||
| 1,610,500 ||
| 541,500 ||
| 724,400 ||
| 12,100 ||
| 8,097,900
|-
| align=left|1963 Census
| 7,003,300 ||
| 1,958,400 ||
| 724,000 ||
| 884,900 ||
| 11,400 ||
| 10,582,000
|-
| align=left|1971 Census
| 8,536,868 ||
| 2,238,666 ||
| 901,785 ||
| 1,004,326 ||
| 8,252 ||
| 12,689,897
|-
| align=left|1981 Census
| 10,288,325 ||
| 2,297,806 ||
| 1,121,717 ||
| 1,130,568 ||
| 8,334 ||
| 14,846,750
|-
| align=left|2001 Census
| colspan=11|
|-
| align=left|2012 Census
| 14,272,056 ||
| 2,561,299 ||
| 1,967,523 ||
| 1,552,161 ||
| 6,400 ||
| 20,359,439
|}
Migration
Immigration
As of 2017, 40,018 foreign-born people lived in Sri Lanka per United Nations' population division.
{|class="wikitable sortable"
|-
! Country of birth
! Population (2017)
|-
|
|10,814
|-
|
|5,107
|-
|
|2,482
|-
|
|1,755
|-
|
|1,689
|-
|
|1,417
|-
|
|1,409
|-
|
|1,193
|-
|
|925
|-
|
|849
|-
|
|829
|-
|
|741
|-
|
|674
|-
|
|613
|-
|
|612
|-
|
|611
|-
|
|561
|-
|}
Net Migration
{| class="wikitable" style="text-align:center;"
|+ Sri Lanka – Net Migration and Mid-Year Population (2013–2024)
! Time Period !! Year !! Net Migration !! Mid-Year Population (‘000)
|-
| July 2012 – June 2013 || 2013 || −71,730 || 20,483
|-
| July 2013 – June 2014 || 2014 || −44,714 || 20,675
|-
| July 2014 – June 2015 || 2015 || −17,055 || 20,870
|-
| July 2015 – June 2016 || 2016 || 34,995 || 21,107
|-
| July 2016 – June 2017 || 2017 || 57,028 || 21,351
|-
| July 2017 – June 2018 || 2018* || 32,826 || 21,574
|-
| July 2018 – June 2019 || 2019* || −54,681 || 21,707
|-
| July 2019 – June 2020 || 2020* || −44,160 || 21,919
|-
| July 2020 – June 2021 || 2021* || 77,600 || 22,152
|-
| July 2021 – June 2022 || 2022* || −85,572 || 22,177
|-
| July 2022 – June 2023 || 2023* || −222,715 || 22,033
|-
| July 2023 – June 2024 || 2024* || −176,932 || 21,889
|}
<small>Note: * Provisional data.</small>