• county
  • FIPS 39107
  • Largest town: Celina

Mercer County, Ohio

Mercer County had 42,648 residents in the Census Vintage 2024 estimate, on 462.5 square miles of land. It ranks 57th of 88 in Ohio by population and 36th by land area.

Population
42,648
#57 of 88 in Ohio · #1,137 in US
Area
462.5 sq mi
#36 of 88 in Ohio · #2,221 in US
Density
92 / sq mi
#60 of 88 in Ohio · #971 in US
Median household income
$79,974
#12 of 88 in Ohio · #475 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Mercer County within Ohio. Pin: Columbus.

Measure from here

Tools and pages that start from Mercer County

Mercer County population, land area and income

Mercer County had 42,648 residents in the Census Vintage 2024 estimate, on 462.5 square miles of land. It ranks 57th of 88 in Ohio by population and 36th by land area. That works out to 92.2 people per square mile, near the US average of 96.3, and above the national county median.

The median county-equivalent in Ohio has 58,250 residents; Mercer County is somewhat smaller.

Its SAIPE 2023 median household income of $79,974 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

42,648

3144th1st

1137th of 3,144 (US)

Land area

462 sq mi

3144th1st

2221st of 3,144 (US)

Density

92.2 / sq mi

3144th1st

971st of 3,144 (US)

Median household income

$79,974

3143rd1st

475th of 3,143 (US)

Rank within Ohio (88)

Population

42,648

88th1st

57th of 88 (OH)

Land area

462 sq mi

88th1st

36th of 88 (OH)

Density

92.2 / sq mi

88th1st

60th of 88 (OH)

Median household income

$79,974

88th1st

12th of 88 (OH)

How Mercer County's population changed since 2020

Mercer County gained 116 residents between the July 2020 and July 2024 estimates, a rise of 0.3%. That ranks 30th of 88 in Ohio for growth. The median Ohio county changed by -0.2%, and the state as a whole by +0.7%.

Since the April 2020 estimates base, Mercer County recorded 2,717 births and 1,983 deaths, a natural change of +734. Net international migration added +202 and net domestic migration, people moving to or from other US counties, came to -815. The largest single component was domestic migration, which removed 815 people.

42.5k202042.4k202142.4k202242.4k202342.6k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
2,717
Deaths
1,983
Net international migration
+202
Net domestic migration
-815
Change, July 2023 to July 2024
+200

Where Mercer County is

The Census internal point of Mercer County is at 40.535300, -84.632100. It sits in UTM zone 16N. The map shades Ohio's 88 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Mercer County outlined. Dots are towns of 1,000+ people with residents in it.

Shelby County: -0.4%Defiance County: +1.0%Darke County: -0.8%Seneca County: -0.6%Wood County: +0.6%Fayette County: -0.7%Clark County: -0.7%Hocking County: -2.2%Jackson County: +0.2%Miami County: +2.7%Richland County: -0.1%Union County: +13.7%Auglaize County: -1.2%Hancock County: +0.1%Morgan County: -1.6%Van Wert County: -0.1%Hardin County: -1.0%Paulding County: -0.3%Portage County: +1.2%Delaware County: +10.6%Harrison County: -3.1%Ross County: -1.3%Crawford County: -0.9%Clinton County: -0.0%Henry County: -0.5%Pike County: -0.0%Cuyahoga County: -1.7%Highland County: +1.0%Knox County: +1.7%Ottawa County: -1.5%Huron County: -0.6%Erie County: -2.2%Holmes County: +1.0%Lawrence County: -4.0%Marion County: -0.6%Fairfield County: +5.2%Putnam County: -0.6%Guernsey County: -0.5%Vinton County: -2.1%Gallia County: -1.2%Trumbull County: -0.7%Wayne County: -0.2%Perry County: +0.6%Ashland County: -0.1%Fulton County: -1.4%Brown County: +1.4%Lucas County: -1.1%Stark County: -0.1%Medina County: +1.1%Belmont County: -2.4%Williams County: -1.4%Mahoning County: -1.0%Noble County: +1.1%Greene County: +2.5%Preble County: -0.5%Allen County: -1.2%Athens County: +1.3%Jefferson County: -2.0%Adams County: +0.8%Monroe County: -2.3%Washington County: -2.2%Logan County: -0.1%Franklin County: +2.4%Warren County: +5.3%Wyandot County: -2.1%Licking County: +3.4%Hamilton County: +0.8%Clermont County: +2.6%Butler County: +2.2%Coshocton County: +1.1%Geauga County: -0.0%Sandusky County: -0.0%Ashtabula County: -0.6%Carroll County: -0.9%Tuscarawas County: -1.2%Morrow County: +2.7%Montgomery County: +0.1%Mercer County: +0.3%Lake County: -0.1%Pickaway County: +6.0%Madison County: +3.8%Muskingum County: +0.1%Meigs County: -3.0%Columbiana County: -1.8%Lorain County: +2.7%Scioto County: -2.8%Champaign County: +0.4%Summit County: -0.3%
Change 2020 to 2024
  1. < -1.4%
  2. < -0.6%
  3. < -0.0%
  4. < +1.1%
  5. ≥ +1.1%
no data

Orange pin: Mercer County internal point. Dark pin: Columbus.

Internal point

Decimal
40.535300, -84.632100
DMS
40°32'7.08"N 84°37'55.56"W
UTM
16N 700545.1E 4489867.1N
Geohash
dp5yd5hz1
Plus code
86GQG9P9+45

Towns in Mercer County

5 incorporated places of 1,000+ people have residents in Mercer County, 20,787 people together, or 49% of the county. Each figure counts only the part of the town inside Mercer County; towns marked "part" extend into another county. The largest is Celina with 10,945.

  1. 01Celina10,945
  2. 02Coldwater4,729
  3. 03St. Henry2,608
  4. 04Fort Recovery1,474
  5. 05Rockford1,031
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Mercer County

The Census 2024 county adjacency file lists 6 neighbors for Mercer County, including 2 across a state line. The most populous is Darke County, OH, with 51,462 residents. Distances run between Census internal points in a straight line.

Distance to Columbus and the nearest big city

Columbus is 94.7 miles ESE of Mercer County's internal point in a straight line. The nearest place of 100,000 or more is Fort Wayne, IN (population 273,203), 46.6 miles away. The nearest place of 10,000 or more is Celina, OH (population 10,945), 4.0 miles away.

Mercer County FIPS code

The FIPS code of Mercer County is 39107: state code 39 for Ohio plus county code 107. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $79,974.

Questions people ask

What is the population of Mercer County, Ohio?

The Census Vintage 2024 estimate for July 1, 2024 is 42,648. That is up 116 people (0.3%) from the July 2020 estimate of 42,532.

What is the FIPS code of Mercer County?

39107. The first two digits (39) are Ohio; the last three (107) identify the county.

What is the largest town in Mercer County?

Celina, with 10,945 residents inside Mercer County in 2024.

Which counties border Mercer County?

6 county-equivalents border it in the Census 2024 adjacency file: Darke County, OH; Shelby County, OH; Auglaize County, OH; Adams County, IN; Van Wert County, OH; Jay County, IN.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.