Share of the population by age and sex, five-year groups
Montana population pyramid, 2020
Year
20201,087,156 people lived in Montana on July 1, 2020: the 44th-largest population among the 50 states and the District of Columbia. The median age was 40.5 years (United States: 38.7); more residents are 65 or older (20.0%) than under 15 (17.9%): an ageing, top-heavy pyramid. There were 100.8 men for every 100 women. Since 2010 the population has grown by 9.7%. Source: U.S. Census Bureau, Population Estimates Program, Vintage 2025 estimates (resident population on July 1; public domain). Median age, shares, dependency ratios and rankings are calculated by PopulationPyramid.net from these estimates; the Census Bureau does not endorse this site.
Show the population by age group, 2020
| Age | Men | Women | Total | Share |
|---|---|---|---|---|
| 0-4 | 30,575 | 29,103 | 59,678 | 5.5% |
| 5-9 | 33,709 | 32,178 | 65,887 | 6.1% |
| 10-14 | 35,412 | 33,529 | 68,941 | 6.3% |
| 15-19 | 34,542 | 32,523 | 67,065 | 6.2% |
| 20-24 | 34,745 | 32,809 | 67,554 | 6.2% |
| 25-29 | 34,258 | 32,435 | 66,693 | 6.1% |
| 30-34 | 36,080 | 34,305 | 70,385 | 6.5% |
| 35-39 | 35,655 | 34,479 | 70,134 | 6.5% |
| 40-44 | 32,494 | 31,209 | 63,703 | 5.9% |
| 45-49 | 29,647 | 28,486 | 58,133 | 5.3% |
| 50-54 | 30,094 | 30,115 | 60,209 | 5.5% |
| 55-59 | 35,449 | 36,769 | 72,218 | 6.6% |
| 60-64 | 38,633 | 40,712 | 79,345 | 7.3% |
| 65-69 | 36,716 | 37,745 | 74,461 | 6.8% |
| 70-74 | 29,290 | 29,324 | 58,614 | 5.4% |
| 75-79 | 18,787 | 19,449 | 38,236 | 3.5% |
| 80-84 | 11,066 | 12,748 | 23,814 | 2.2% |
| 85+ | 8,644 | 13,442 | 22,086 | 2.0% |
| Rank | State | Residents | Relative |
|---|---|---|---|
| 41 | New Hampshire | 1,378,752 | |
| 42 | Maine | 1,364,546 | |
| 43 | Rhode Island | 1,096,487 | |
| 44 | Montana | 1,087,156 | |
| 45 | Delaware | 991,890 | |
| 46 | South Dakota | 887,808 | |
| 47 | North Dakota | 779,612 |