All 50 States, Ranked by the Median Age of Their Residents

Delaware ratified the Constitution on December 7, 1787, which makes it the oldest state in the U.S. Pennsylvania and New Jersey followed suit that same month. If you’re talking about the age of a state’s population, though, the oldest three are a little farther north—namely, Maine, New Hampshire, and Vermont.

For his data visualization blog FlowingData, statistician Nathan Yau charted the median age of each state’s (plus Washington, D.C.’s and Puerto Rico’s) population using information from the 2021 American Community Survey (ACS). Like the decennial census, the ACS is managed by the U.S. Census Bureau; unlike the census, which only happens once every 10 years, the ACS is conducted every month of every year. It’s not comprehensive—it is sent to only about 3.5 million addresses at a time—but the frequency means that the data is often more up-to-date than the census’s.

In case you haven’t thought much about medians since your high school math classes, here’s a refresher: The median value in a dataset is the one in the very middle when all the numbers are in order. The average value is what you get when you add up all the values and divide them by the number of values in the dataset. If there are outliers on either end, they can skew the average—but the median is always dead-center, giving equal weight to each value.

The median age of Mainers is 44.7, more than a year and a half older than New Hampshire and two years older than Vermont. Puerto Rico broke up the New England trio, coming second to last with a median age of 43.1.

The other territory included in the rankings is the second youngest: Washington, D.C.’s median age is 34.3, three years older than first-place finisher Utah. Those two places illustrate one of the most interesting takeaways from the data: As Yau puts it, “the distribution of age doesn’t shift evenly all the way down.” D.C. is so young because a significant number of its residents are in their twenties and thirties, while Utah’s low median age is mostly because it’s home to tons of children.

You can see your state’s median age in the list below, and explore all the age bracket breakdowns via FlowingData.