The map above shows Idaho and Utah side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Idaho vs Utah Geography
Land area: Idaho has a land area of 82,645 square miles (214,051 km²), while Utah has 82,596 square miles (213,922 km²). Idaho and Utah have about the same land area.
Total area: Idaho: 83,569 square miles (216,441 km²) vs Utah: 84,898 square miles (219,885 km²), including inland and coastal water. Idaho and Utah have about the same total area.
Length: Idaho is 483 miles (778 km) long from north to south; Utah is 436 miles (702 km). Idaho's north-south length is 1.1 times (11%) longer than Utah's.
Width: Idaho spans 352 miles (566 km) east to west; Utah spans 268 miles (431 km). Idaho's east-west width is 1.3 times (31%) wider than Utah's.
Highest point: Idaho's highest point is Borah Peak at 12,631 feet (3,850 m); Utah's is Kings Peak at 13,512 feet (4,118 m). Kings Peak is 881 feet higher than Borah Peak.
Lowest point: Idaho's lowest point is Snake River at 718 feet; Utah's is Beaver Dam Wash at 2,180 feet. Idaho's lowest point is 1,462 feet lower.
Idaho vs Utah Population and History
Population: Idaho has a population of 2,001,619 (2024), while Utah has 3,503,613 (2024). Utah's population is 1.8 times (75%) larger than Idaho's.
Population density: Idaho: 24.2 people per square mile vs Utah: 42.4. Utah's population density is 1.8 times (75%) higher than Idaho's.
Biggest city: Idaho's biggest city is Boise with 237,963 people; Utah's is Salt Lake City with 217,783. Boise's population is 1.1 times (9%) larger than Salt Lake City's.
Largest metro area: Idaho's largest metropolitan area is Boise City, ID metro area (845,877 people) vs Utah's Salt Lake City-Murray, UT metro area (1,300,762). Salt Lake City-Murray, UT metro area's population is 1.5 times (54%) larger than Boise City, ID metro area's.
History: Idaho: Admitted to the Union on July 3, 1890, as the 43rd state. Utah: Admitted to the Union on January 4, 1896, as the 45th state. In its current form, Idaho is the older of the two by 6 years.
Idaho vs Utah Economy
GDP: Idaho's GDP is $129.0 billion (2024) vs Utah's $299.5 billion. Utah's economic output is 2.3 times (132%) larger than Idaho's.
GDP per capita: Idaho: $64,457 per person vs Utah: $85,475. Utah's GDP per capita is 1.3 times (33%) higher than Idaho's.
Average income: Idaho: $62,323 vs Utah: $67,333 average income per person (per capita personal income). Utah's average income is 1.1 times (8%) higher than Idaho's.
Idaho vs Utah Counties
Number of counties: Idaho has 44 counties, while Utah has 29. Idaho's county count is 1.5 times (52%) higher than Utah's.
Biggest county by area: Idaho's largest county is Idaho County at 8,478 square miles; Utah's is San Juan County at 7,824 square miles. Idaho County's land area is 1.1 times (8%) larger than San Juan County's.
Smallest county by area: Idaho: Payette County (407 sq mi) vs Utah: Davis County (325 sq mi). Payette County's land area is 1.3 times (25%) larger than Davis County's.
Most populous county: Idaho: Ada County (535,799 people) vs Utah: Salt Lake County (1,216,274 people). Salt Lake County's population is 2.3 times (127%) larger than Ada County's.
Least populous county: Idaho: Clark County (794 people) vs Utah: Daggett County (956 people). Daggett County's population is 1.2 times (20%) larger than Clark County's.
Richest county: Idaho: Blaine County ($202,612 per capita income) vs Utah: Summit County ($280,510). Summit County's income is 1.4 times (38%) richer than Blaine County's.
Poorest county: Idaho: Madison County ($29,485 per capita income) vs Utah: Beaver County ($39,179). Beaver County's income is 1.3 times (33%) richer than Madison County's.
Idaho vs Utah Taxes
State income tax: Idaho has a top income tax rate of 5.3%, while Utah has a top income tax rate of 4.5%. Idaho's top rate is 0.8 percentage points higher.
Property tax: Idaho: 0.43% effective rate vs Utah: 0.49% of home value per year. Utah's rate is 0.06 percentage points higher.
Sales tax: Idaho: 6.03% combined state and average local rate vs Utah: 7.42%. Utah's combined rate is 1.39 percentage points higher.
Official Websites
Idaho official website · Utah official website
More Size Comparisons
All Idaho size comparisons · All Utah 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.