| ZIP Codes: | 48 ZIP Codes (32 Standard, 9 PO Box, 7 Unique) [See All] |
| Area Codes: | 326 / 937 |
| Timezone: | Eastern (GMT -05:00) |
| Local Time: | 2:13:21 PM |
| Population: | 537,404 [See All] |
| FIPS: | 39113 |
| CBSA: | Dayton-Kettering-Beavercreek, OH |
| Land Area: | 477 sq mi |
| Water Area: | 3 sq mi |
| Coordinates: | 39.7472, -84.2213 |
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537,404 residents live across 48 ZIPs covering 477 sq mi, served by 10 distinct USPS-recognized cities.
Population moved from 531,781 to 537,236 from 2014 to 2024 — a +1.0% change. 14 ZIPs gained residents, 18 lost.
The county's wealthiest ZIP 45430 (Dayton, $115,461 median) and poorest ZIP 45417 (Dayton, $36,945) are 9.3 miles apart — a 3.1× income gap across local geography.
Median home values vary 4.8× across this county — from $75,100 in 45417 (Dayton) to $362,700 in 45458 (Dayton).
Density varies 62× across the county — from 99 people/sq mi in 45325 (Farmersville) to 6,155 in 45410 (Dayton).
Most of the decade's growth concentrated around Dayton — top growth ZIPs averaged +20.4% over the past ten years ( 45458 , 45439 and 45419 ).
Educational attainment ranges from 10.2% bachelor's+ in 45404 (Dayton) to 62.7% in 45409 (Dayton) — the breadth of educational profiles across the area.
Within Ohio, this is the #4 most populous of 88 counties and ranks #47 for median household income .
Hosts 4 single-entity Unique ZIPs: 45469University Of Dayton ; 45422Montgomery Cnty Admnstrv ; 45482Dayton Business Reply Mail ; and 45412National City Bank .
Weighted by population, the typical household earns about $71,893 across the county — reflecting what a typical resident sees, not a simple ZIP average.
32.7% of adults age 25+ hold a bachelor's degree or higher (120,881 of 369,997 reporting). The most-educated ZIPs cluster around Dayton.
32 Standard delivery, 9 PO Box only, 7 single-entity Unique ZIPs serve this county.
2 ZIPs in this county where more than 60% of adults 25+ hold a bachelor's degree — typically college campuses, research enclaves, or tech corridors.
7 ZIP codes in this county serve a single facility — typically theme parks, universities, large corporations, airports, or government complexes.
Median household income spans 3.1× between the wealthiest and poorest ZIPs — a sign of significant intra-county inequality.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 45424 | Dayton | Standard | 50,725 | $80,605 | 31.5 | 0.7% |
| 45458 | Dayton | Standard | 38,712 | $110,150 | 20.6 | 26.3% |
| 45342 | Miamisburg | Standard | 36,152 | $84,907 | 34.7 | -1.1% |
| 45459 | Dayton | Standard | 28,553 | $89,592 | 14.7 | 3.5% |
| 45417 | Dayton | Standard | 28,186 | $36,945 | 35.3 | -11.2% |
| 45429 | Dayton | Standard | 26,347 | $80,210 | 10.1 | 3.9% |
| 45420 | Dayton | Standard | 24,411 | $60,588 | 6.3 | -5.8% |
| 45440 | Dayton | Standard | 22,358 | $82,383 | 9.0 | 7.7% |
| 45414 | Dayton | Standard | 21,167 | $54,485 | 24.2 | 0.8% |
| 45322 | Englewood | Standard | 20,884 | $75,349 | 21.8 | -3.1% |
| 45406 | Dayton | Standard | 19,991 | $41,796 | 5.0 | -2.1% |
| 45449 | Dayton | Standard | 19,066 | $63,800 | 7.0 | 3.8% |
| 45405 | Dayton | Standard | 18,955 | $43,973 | 4.1 | 3.5% |
| 45419 | Dayton | Standard | 17,008 | $92,264 | 3.7 | 17.4% |
| 45409 | Dayton | Standard | 15,293 | $87,283 | 3.6 | -2.1% |
| 45377 | Vandalia | Standard | 14,888 | $77,398 | 20.1 | -0.8% |
| 45410 | Dayton | Standard | 14,694 | $46,651 | 2.4 | -6.8% |
| 45426 | Dayton | Standard | 14,114 | $51,908 | 18.8 | -5.5% |
| 45403 | Dayton | Standard | 13,608 | $38,323 | 3.1 | -11.0% |
| 45415 | Dayton | Standard | 12,465 | $81,176 | 6.2 | -1.7% |
| 45439 | Dayton | Standard | 11,914 | $52,035 | 6.7 | 17.4% |
| 45309 | Brookville | Standard | 11,876 | $75,409 | 63.8 | -5.7% |
| 45404 | Dayton | Standard | 9,826 | $38,874 | 7.2 | -0.9% |
| 45402 | Dayton | Standard | 9,407 | $48,401 | 4.7 | -11.6% |
| 45327 | Germantown | Standard | 9,315 | $94,741 | 48.0 | 0.3% |
| 45430 | Dayton | Standard | 7,371 | $115,461 | 5.1 | -1.8% |
| 45345 | New Lebanon | Standard | 6,110 | $80,280 | 21.3 | 4.1% |
| 45416 | Dayton | Standard | 5,640 | $46,174 | 1.8 | -3.9% |
| 45315 | Clayton | Standard | 4,905 | $92,333 | 10.9 | 15.4% |
| 45325 | Farmersville | Standard | 2,470 | $81,250 | 25.0 | 2.2% |
| 45354 | Phillipsburg | PO Box | 553 | $66,625 | 0.2 | -3.7% |
| 45428 | Dayton | PO Box | 272 | — | 0.2 | -12.5% |
| 45469 | Dayton | Unique | 168 | — | 0.0 | — |
| 45423 | Dayton | Standard | 0 | — | 0.0 | — |
| 45422 | Dayton | Unique | — | — | 0.0 | — |
| 45482 | Dayton | Unique | — | — | 0.0 | — |
| 45437 | Dayton | PO Box | — | — | 0.0 | — |
| 45412 | Dayton | Unique | — | — | 0.0 | — |
| 45441 | Dayton | PO Box | — | — | 0.0 | — |
| 45479 | Dayton | Standard | — | — | 0.0 | — |
| 45413 | Dayton | PO Box | — | — | 0.0 | — |
| 45470 | Dayton | Unique | — | — | 0.0 | — |
| 45401 | Dayton | PO Box | — | — | 0.0 | — |
| 45475 | Dayton | PO Box | — | — | 0.0 | — |
| 45448 | Dayton | Unique | — | — | 0.0 | — |
| 45343 | Miamisburg | PO Box | — | — | 0.0 | — |
| 45490 | Dayton | PO Box | — | — | 0.0 | — |
| 45481 | Dayton | Unique | — | — | 0.0 | — |