County data desk
Where is Missouri's older population oldest? DeKalb County, where 16.7 percent of residents aged 65 and over are 85 and over.
Not how old a county is, but how deep into old age its older population runs. One published column divided by another, for all 115 county equivalents, with the 25 highest ratios printed here and every St. Louis region county sitting below the top 45.
Methodology
- Metric
- Residents aged 85 and over divided by residents aged 65 and over, expressed as a percentage, sorted descending. This ratio is computed by this desk from two published Census columns and is not itself published by the Bureau; both inputs are printed in the table so the division is visible. Rank is taken on the unrounded ratio and the display is rounded to one decimal, which is why positions 25 and 26 both show 12.1 percent.
- Source
- U.S. Census Bureau, Population Estimates Program, Vintage 2024 county characteristics file cc-est2024-agesex-29.csv, columns AGE85PLUS_TOT, AGE65PLUS_TOT and POPESTIMATE, rows coded YEAR 6. AGE85PLUS_TOT is a subset of AGE65PLUS_TOT.
- Reference date
- July 1, 2024.
- Item set
- All 115 Missouri county equivalents, fixed before any value was read. The 25 highest ratios are published here. Nine of the 25 also appear in the statewide top 20 by share aged 65 and over; sixteen do not.
- Pulled
- September 10, 2026
- Licence
- Public domain, a work of the United States government.
The six highest ratios in the state. Statewide, 124,625 of 1,169,583 residents aged 65 and over are aged 85 and over, 10.7%.
| # | County | 85+ as share of 65+ | Aged 85 and over | Aged 65 and over | Total population | Share 65 and over |
|---|---|---|---|---|---|---|
| 1 | DeKalb County | 16.7% | 355 | 2,126 | 9,884 | 21.5% |
| 2 | Grundy County | 16.0% | 350 | 2,188 | 9,766 | 22.4% |
| 3 | Scotland County | 15.9% | 149 | 935 | 4,698 | 19.9% |
| 4 | Holt County | 15.3% | 165 | 1,076 | 4,241 | 25.4% |
| 5 | Nodaway County | 15.3% | 596 | 3,895 | 20,503 | 19.0% |
| 6 | Mercer County | 15.1% | 126 | 836 | 3,452 | 24.2% |
| 7 | Livingston County | 14.5% | 432 | 2,983 | 14,658 | 20.4% |
| 8 | Sullivan County | 13.9% | 182 | 1,307 | 5,750 | 22.7% |
| 9 | Chariton County | 13.8% | 257 | 1,865 | 7,397 | 25.2% |
| 10 | Reynolds County | 13.4% | 200 | 1,497 | 5,927 | 25.3% |
| 11 | Vernon County | 13.1% | 549 | 4,177 | 19,787 | 21.1% |
| 12 | Dade County | 13.1% | 246 | 1,875 | 7,622 | 24.6% |
| 13 | Shelby County | 13.1% | 171 | 1,310 | 5,926 | 22.1% |
| 14 | St. Clair County | 13.0% | 330 | 2,539 | 9,848 | 25.8% |
| 15 | Pettis County | 12.9% | 1,024 | 7,966 | 43,791 | 18.2% |
| 16 | Perry County | 12.8% | 512 | 3,990 | 19,100 | 20.9% |
| 17 | Harrison County | 12.8% | 245 | 1,917 | 8,186 | 23.4% |
| 18 | Stoddard County | 12.7% | 759 | 5,954 | 28,438 | 20.9% |
| 19 | Cape Girardeau County | 12.7% | 1,981 | 15,568 | 83,658 | 18.6% |
| 20 | Hickory County | 12.7% | 358 | 2,818 | 8,766 | 32.1% |
| 21 | Worth County | 12.5% | 64 | 510 | 1,872 | 27.2% |
| 22 | Dunklin County | 12.4% | 644 | 5,174 | 27,002 | 19.2% |
| 23 | Lawrence County | 12.3% | 873 | 7,114 | 39,151 | 18.2% |
| 24 | Atchison County | 12.2% | 158 | 1,296 | 5,139 | 25.2% |
| 25 | Lewis County | 12.1% | 237 | 1,954 | 9,852 | 19.8% |
Sixty three of the 115 counties sit above the statewide ratio of 10.7%. The 25 counties here hold 10,963 residents aged 85 and over between them, 8.8 percent of the state's 124,625.
What this ratio measures, and what the share column beside it does not
The last column of the table, share aged 65 and over, is the figure this desk ranks on the oldest counties page. It says how much of a county is in the older band. The ratio ranked here says something different: of the people already in that band, how many have passed 85. A county can score high on one and low on the other, and several do.
Stone County, first in the state by share at 33.1 percent, ranks 107th of 115 on this ratio at 9.2%. Camden County, fourth by share at 31.1 percent, ranks 112th at 8.5%, in the bottom four. Benton County, second by share, ranks 96th. The lake counties are old by share because older adults have moved there, and the ones who move are, on this evidence, mostly under 85.
The counties that lead this ratio are of a different kind. DeKalb, Grundy, Scotland, Holt, Nodaway and Mercer are northern counties with small bases: DeKalb's 16.7 percent rests on 355 residents aged 85 and over out of 2,126 aged 65 and over. An older population that runs deep into the oldest band, in a county that is not large, is the pattern across the top of this table.
No St. Louis region county reaches the top 45
St. Louis County, which holds 22,623 residents aged 85 and over, the largest count in Missouri, ranks 48th on this ratio at 11.3 percent. St. Charles County ranks 68th at 10.5 percent, Franklin County 91st at 10.0 percent, the city of St. Louis 95th at 9.9 percent, Lincoln County 110th at 8.7 percent and Warren County 111th at 8.5 percent.
Jefferson County ranks 114th of 115 at 7.3 percent, the second lowest ratio in the state, one place above McDonald County. Its 3,040 residents aged 85 and over sit inside an older population of 41,443, and that is the same reading the regional table gives on the 85 and over page: Jefferson's older population is large and comparatively young within the band.
For the region, then, the count of the oldest old is concentrated in one county and the depth of the band is unremarkable everywhere. Both facts are true and they point at different planning questions.
Cautions
Seven counties in the top 25 have fewer than 200 residents aged 85 and over. Worth County's 12.5 percent rests on 64 people; Mercer County's 15.1 percent on 126; Scotland County's 15.9 percent on 149. A ratio built on a cell that small moves a full percentage point on a change of a dozen residents, and these are modelled estimates, not counts. Read the top of this table as a pattern, not as a league table of precise positions.
A second cut, residents aged 85 and over as a share of total county population, was considered and not built: measured against the existing share ranking its top 20 overlaps by 14 counties, which would be the same page under a new title. This ratio was chosen because it asks a different question of the file.
Age is not need. Nothing in this table says anything about health, independence, living arrangements or the use of caregiver services, and this desk draws no such conclusion from it. Sources and limits are on the methodology page.
Back to the region at a glance · The 85 and over layer, regional table