Oakland County area

Population and density of Oakland County

The Census Bureau estimates that 1,288,337 people lived in Oakland County on July 1, 2025. That ranks #34 of 3,222 county equivalents nationally and #2 of 83 in Michigan. Since the April 1, 2020 estimates base of 1,274,375, the population has grown by 13,962 (+1.1%), compared with +0.5% for Michigan as a whole.

With 867.4 square miles of land, that is 1,485 people per square mile (573 per km²), placing Oakland County #117 nationally for density and #3 in Michigan. The median county equivalent has 47 people per square mile; the Michigan median is 62. Put another way, there are about 0.431 acres of land per resident.

U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.

Cities and towns in Oakland County

Oakland County is divided into 52 municipalities and townships. In Michigan, county subdivisions are local governments, and together they cover all of the county’s land and residents.

The most populous is Troy city, with 88,733 residents (6.9% of the county). The largest by land is Oakland charter township, at 36.3 mi², or 4.2% of the county’s land. The county seat, Pontiac city, has 62,077 residents. Among those with at least 1,000 residents in 2020, Lyon charter township grew fastest since then (+15.5%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each subdivision inside Oakland County. Land: 2026 Census Gazetteer. How communities are listed.

Metropolitan area

Oakland County is a central county of the Detroit-Warren-Dearborn, MI Metropolitan Statistical Area, in the Warren-Troy-Farmington Hills, MI metropolitan division. Its 6 county equivalents have 4,390,913 residents on 3,892.9 square miles of land; Oakland County accounts for 22.3% of the land and 29.3% of the residents. By combined land it ranks #75 of 393 metropolitan areas, and #14 by population. It belongs to the Detroit-Warren-Ann Arbor, MI Combined Statistical Area.

ZIP codes

71 ZIP Code Tabulation Areas have land in Oakland County; 66 of them have most of their land inside the county, and the others mainly cover neighboring areas.

4800948017480254803048033480344806748069480704807148072480734807548076480834808448085480984816548167481784822048237483014830248304483064830748309483204832248323483244832648327483284832948331483344833548336483404834148342483464834848350483564835748359483604836248363483674837048371483744837548377483804838148382483834838648390483934842848430484394844248462

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Oakland County

Oakland County shares a land border with 6 county equivalents. It has more land than every one of them. The largest neighbor is Washtenaw County (706 mi²) and the smallest is Macomb County (479.4 mi²). Together with its neighbors, Oakland County forms a block of 4,514.3 mi² of land, of which it holds 19.2%.

How big is Oakland County compared with U.S. states?

Oakland County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. Michigan’s county land could hold about 65 areas the size of Oakland County.

Another way to picture it: the same land area would fill a square about 29.5 miles (47.4 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.

State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.

What stands out about Oakland County?

Oakland County has more land than 2,275 of the other 3,221 county equivalents in the dataset.

A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.

Does including water change its rank?

Using land plus water places Oakland County at #941 nationally by total area, 6 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 4.4%, compared with a national county-equivalent median of 1.2% — 3.2 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.

Closest positions in the national land ranking

These entries sit immediately beside Oakland County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.