The map above shows Idaho and Ohio side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Idaho vs Ohio Geography
Land area: Idaho has a land area of 82,645 square miles (214,051 km²), while Ohio has 40,859 square miles (105,824 km²). Idaho's land area is 2.0 times (102%) larger than Ohio's.
Total area: Idaho: 83,569 square miles (216,441 km²) vs Ohio: 44,826 square miles (116,098 km²), including inland and coastal water. Idaho's total area is 1.9 times (86%) larger than Ohio's.
Length: Idaho is 483 miles (778 km) long from north to south; Ohio is 291 miles (468 km). Idaho's north-south length is 1.7 times (66%) longer than Ohio's.
Width: Idaho spans 352 miles (566 km) east to west; Ohio spans 317 miles (510 km). Idaho's east-west width is 1.1 times (11%) wider than Ohio's.
Highest point: Idaho's highest point is Borah Peak at 12,631 feet (3,850 m); Ohio's is Campbell Hill at 1,547 feet (472 m). Borah Peak is 11,084 feet higher than Campbell Hill.
Lowest point: Idaho's lowest point is Snake River at 718 feet; Ohio's is Ohio River at 455 feet. Ohio's lowest point is 263 feet lower.
Idaho vs Ohio Population and History
Population: Idaho has a population of 2,001,619 (2024), while Ohio has 11,883,304 (2024). Ohio's population is 5.9 times (494%) larger than Idaho's.
Population density: Idaho: 24.2 people per square mile vs Ohio: 290.8. Ohio's population density is 12.0 times higher than Idaho's.
Biggest city: Idaho's biggest city is Boise with 237,963 people; Ohio's is Columbus with 933,263. Columbus' population is 3.9 times (292%) larger than Boise's.
Largest metro area: Idaho's largest metropolitan area is Boise City, ID metro area (845,877 people) vs Ohio's Cincinnati, OH-KY-IN metro area (2,302,815). Cincinnati, OH-KY-IN metro area's population is 2.7 times (172%) larger than Boise City, ID metro area's.
History: Idaho: Admitted to the Union on July 3, 1890, as the 43rd state. Ohio: Admitted to the Union on March 1, 1803, as the 17th state. In its current form, Ohio is the older of the two by 87 years.
Idaho vs Ohio Economy
GDP: Idaho's GDP is $129.0 billion (2024) vs Ohio's $923.1 billion. Ohio's economic output is 7.2 times (616%) larger than Idaho's.
GDP per capita: Idaho: $64,457 per person vs Ohio: $77,684. Ohio's GDP per capita is 1.2 times (21%) higher than Idaho's.
Average income: Idaho: $62,323 vs Ohio: $64,464 average income per person (per capita personal income). Idaho and Ohio have about the same average income.
Idaho vs Ohio Counties
Number of counties: Idaho has 44 counties, while Ohio has 88. Ohio's county count is 2.0 times (100%) higher than Idaho's.
Biggest county by area: Idaho's largest county is Idaho County at 8,478 square miles; Ohio's is Ashtabula County at 702 square miles. Idaho County's land area is 12.1 times larger than Ashtabula County's.
Smallest county by area: Idaho: Payette County (407 sq mi) vs Ohio: Lake County (229 sq mi). Payette County's land area is 1.8 times (77%) larger than Lake County's.
Most populous county: Idaho: Ada County (535,799 people) vs Ohio: Franklin County (1,356,303 people). Franklin County's population is 2.5 times (153%) larger than Ada County's.
Least populous county: Idaho: Clark County (794 people) vs Ohio: Vinton County (12,545 people). Vinton County's population is 15.8 times larger than Clark County's.
Richest county: Idaho: Blaine County ($202,612 per capita income) vs Ohio: Delaware County ($96,573). Blaine County's income is 2.1 times (110%) richer than Delaware County's.
Poorest county: Idaho: Madison County ($29,485 per capita income) vs Ohio: Noble County ($34,940). Noble County's income is 1.2 times (19%) richer than Madison County's.
Idaho vs Ohio Taxes
State income tax: Idaho has a top income tax rate of 5.3%, while Ohio has a top income tax rate of 2.75%. Idaho's top rate is 2.55 percentage points higher.
Property tax: Idaho: 0.43% effective rate vs Ohio: 1.22% of home value per year. Ohio's rate is 0.79 percentage points higher.
Sales tax: Idaho: 6.03% combined state and average local rate vs Ohio: 7.29%. Ohio's combined rate is 1.26 percentage points higher.
Official Websites
Idaho official website · Ohio official website
More Size Comparisons
All Idaho size comparisons · All Ohio size comparisons
Area, elevation and boundary figures come from official national statistics and US Census Bureau and Natural Earth boundary data; US state population, economic, county and tax figures come from the US Census Bureau, the Bureau of Economic Analysis and the Tax Foundation. Figures are rounded and for general reference.