Share of the population by age and sex, five-year groups

Population of Montana, 2010–2025 · click to pick a year
Estimates up to 2019 are built on the 2010 Census, those from 2020 on the 2020 Census. A line that steps up or down between 2019 and 2020 reflects this re-basing, not a sudden change in population.

Year

-5 -1   2025  +1 +5

1,144,694 people lived in Montana on July 1, 2025: the 43rd-largest population among the 50 states and the District of Columbia. The median age was 41.2 years (United States: 39.4); more residents are 65 or older (22.2%) than under 15 (16.5%): an ageing, top-heavy pyramid. There were 100.9 men for every 100 women. Since 2010 the population has grown by 15.5%. 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.

Key indicators, 2025
Population
1,144,694
Rank by population
43rd of 51
Median age
41.2
Men per 100 women
100.9
Under 15
16.5%
15–64
61.3%
65 and over
22.2%
Child dependency
26.9
Old-age dependency
36.1
Change since 2010
+15.5%
Dependency ratios count children under 15 or adults 65 and over per 100 residents aged 15 to 64.
Show the population by age group, 2025
AgeMenWomenTotalShare
0-428,85727,60356,4604.9%
5-932,29630,86363,1595.5%
10-1435,28333,77869,0616.0%
15-1937,07934,53071,6096.3%
20-2440,06136,63476,6956.7%
25-2936,19533,72669,9216.1%
30-3437,01835,27572,2936.3%
35-3938,68137,05075,7316.6%
40-4437,77836,62074,3986.5%
45-4933,93432,57266,5065.8%
50-5430,59129,72260,3135.3%
55-5930,90131,12262,0235.4%
60-6435,26937,48472,7536.4%
65-6937,43540,18477,6196.8%
70-7433,89635,68269,5786.1%
75-7925,12426,43651,5604.5%
80-8414,34015,86530,2052.6%
85+10,19114,61924,8102.2%
How Montana compares with similar-sized states, 2025
RankStateResidentsRelative
40 Hawaii 1,432,820
41 New Hampshire 1,415,342
42 Maine 1,414,874
43 Montana 1,144,694
44 Rhode Island 1,114,521
45 Delaware 1,059,952
46 South Dakota 935,094
Frequently asked questions about Montana's population
What is the population of Montana?
Montana had an estimated 1,144,694 residents on July 1, 2025, according to the U.S. Census Bureau, Population Estimates Program. That ranks 43rd among the 51 states and the District of Columbia.
What is the median age in Montana?
The median age in Montana was 41.2 years in 2025, the 11th oldest of the 51 states and DC. That is 1.8 years older than the national median of 39.4.
How many people in Montana are 65 or older?
About 253,772 residents of Montana (22.2%) were 65 or older in 2025, against 16.5% under 15 and 61.3% aged 15 to 64.
What does the population pyramid of Montana show?
In 2025, Montana: more residents are 65 or older (22.2%) than under 15 (16.5%): an ageing, top-heavy pyramid. There were 100.9 men for every 100 women.
How fast is the population of Montana changing?
The population of Montana grew by 15.5% between 2010 and 2025, and by 0.6% in the last year.
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