| ZIP Codes: | 16 ZIP Codes (11 Standard, 4 PO Box, 1 Unique) [See All] |
| Area Codes: | 220 / 326 / 740 / 937 |
| Timezone: | Eastern (GMT -05:00) |
| Local Time: | 2:13:19 PM |
| Population: | 174,684 [See All] |
| FIPS: | 39057 |
| CBSA: | Dayton-Kettering-Beavercreek, OH |
| Land Area: | 406 sq mi |
| Water Area: | 3 sq mi |
| Coordinates: | 39.7224, -83.9481 |
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174,684 residents live across 16 ZIPs covering 406 sq mi, served by 12 distinct USPS-recognized cities.
Population moved from 168,421 to 174,550 from 2014 to 2024 — a +3.6% change. 13 ZIPs gained residents, 2 lost.
The county's wealthiest ZIP 45434 (Dayton, $135,948 median) and poorest ZIP 45324 (Fairborn, $64,979) are 7.0 miles apart — a 2.1× income gap across local geography.
Median home values vary 2.4× across this county — from $145,900 in 45384 (Wilberforce) to $352,000 in 45370 (Spring Valley).
Density varies 30× across the county — from 84 people/sq mi in 45335 (Jamestown) to 2,506 in 45431 (Dayton).
Educational attainment ranges from 25.9% bachelor's+ in 45335 (Jamestown) to 62.3% in 45387 (Yellow Springs) — the breadth of educational profiles across the area.
Within Ohio, this is the #17 most populous of 88 counties and ranks #8 for median household income .
Hosts 1 single-entity Unique ZIP: 45435Wright State University .
Weighted by population, the typical household earns about $84,568 across the county — reflecting what a typical resident sees, not a simple ZIP average.
37.7% of adults age 25+ hold a bachelor's degree or higher (44,718 of 118,491 reporting).
11 Standard delivery, 4 PO Box only, 1 single-entity Unique ZIPs serve this county.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 45324 | Fairborn | Standard | 41,194 | $64,979 | 31.9 | 2.7% |
| 45385 | Xenia | Standard | 40,617 | $76,564 | 138.2 | 4.9% |
| 45431 | Dayton | Standard | 27,951 | $83,175 | 11.2 | 3.6% |
| 45432 | Dayton | Standard | 15,055 | $83,115 | 7.0 | 0.9% |
| 45434 | Dayton | Standard | 12,529 | $135,948 | 11.1 | 6.2% |
| 45305 | Bellbrook | Standard | 11,498 | $123,045 | 13.6 | 3.2% |
| 45335 | Jamestown | Standard | 7,359 | $81,690 | 87.5 | 11.7% |
| 45314 | Cedarville | Standard | 6,536 | $84,844 | 46.9 | 9.5% |
| 45387 | Yellow Springs | Standard | 5,285 | $96,042 | 28.8 | 1.9% |
| 45370 | Spring Valley | Standard | 2,518 | $122,000 | 16.4 | 8.7% |
| 45384 | Wilberforce | PO Box | 1,919 | $67,019 | 2.5 | 25.8% |
| 45433 | Dayton | Standard | 1,508 | $89,615 | 10.7 | -41.8% |
| 45301 | Alpha | PO Box | 224 | — | 0.1 | 69.7% |
| 45307 | Bowersville | PO Box | 216 | $72,500 | 0.0 | -31.6% |
| 45316 | Clifton | PO Box | 141 | $83,125 | 0.0 | 11.0% |
| 45435 | Dayton | Unique | 134 | — | 0.0 | — |