by World Population Review, accessed August 23, 2018
Sri Lanka Population by Year (Projections)
| Year | Population | % Male | % Female | Density (km²) | Growth Rate | |
| 2020 | 21,084,042 | 47.94% | 52.06% | 321.35 | x | 0.00% |
| 2025 | 21,349,942 | 47.75% | 52.25% | 325.41 | 0.25% | |
| 2030 | 21,474,701 | 47.56% | 52.44% | 327.31 | 0.12% | |
| 2035 | 21,491,895 | 47.40% | 52.60% | 327.57 | 0.02% | |
| 2040 | 21,397,716 | 47.27% | 52.73% | 326.13 | -0.09% | |
| 2045 | 21,165,080 | 47.17% | 52.83% | 322.59 | -0.22% | |
| 2050 | 20,792,352 | 47.09% | 52.91% | 316.91 | -0.35% | |
| 2055 | 20,325,944 | 47.05% | 52.95% | 309.80 | -0.45% | |
| 2060 | 19,804,831 | 47.05% | 52.95% | 301.86 | -0.52% | |
| 2065 | 19,255,946 | 47.11% | 52.89% | 293.49 | -0.56% | |
| 2070 | 18,693,181 | 47.20% | 52.80% | 284.91 | -0.59% | |
| 2075 | 18,113,572 | 47.33% | 52.67% | 276.08 | -0.63% | |
| 2080 | 17,514,368 | 47.46% | 52.54% | 266.95 | -0.67% | |
| 2085 | 16,899,516 | 47.57% | 52.43% | 257.58 | -0.71% | |
| 2090 | 16,275,814 | 47.65% | 52.35% | 248.07 | -0.75% | |
| 2095 | 15,650,838 | 47.70% | 52.30% | 238.54 | -0.78% |
Sri Lanka Top 20 Cities by Population
| Name | Population |
| Colombo | 648,034 |
| Mount Lavinia | 219,827 |
| Dehiwala-Mount Lavinia | 219,827 |
| Galkissa | 215,941 |
| Moratuwa | 185,031 |
| Jaffna | 169,102 |
| Negombo | 137,223 |
| Pita Kotte | 118,179 |
| Sri Jayewardenepura Kotte | 115,826 |
| Kandy | 111,701 |
| Trincomalee | 108,420 |
| Kalmunai | 100,171 |
| Galle | 93,118 |
| Point Pedro | 89,810 |
| Batticaloa | 86,742 |
| Katunayaka | 84,643 |
| Valvedditturai | 78,205 |
| Matara | 76,254 |
| Battaramulla South | 75,633 |
| Dambulla | 66,716 |