The map above shows Idaho and Pennsylvania side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Idaho vs Pennsylvania Geography
Land area: Idaho has a land area of 82,645 square miles (214,051 km²), while Pennsylvania has 44,742 square miles (115,882 km²). Idaho's land area is 1.8 times (85%) larger than Pennsylvania's.
Total area: Idaho: 83,569 square miles (216,441 km²) vs Pennsylvania: 46,054 square miles (119,279 km²), including inland and coastal water. Idaho's total area is 1.8 times (81%) larger than Pennsylvania's.
Length: Idaho is 483 miles (778 km) long from north to south; Pennsylvania is 284 miles (458 km). Idaho's north-south length is 1.7 times (70%) longer than Pennsylvania's.
Width: Idaho spans 352 miles (566 km) east to west; Pennsylvania spans 307 miles (495 km). Idaho's east-west width is 1.1 times (15%) wider than Pennsylvania's.
Highest point: Idaho's highest point is Borah Peak at 12,631 feet (3,850 m); Pennsylvania's is Mount Davis at 3,210 feet (978 m). Borah Peak is 9,421 feet higher than Mount Davis.
Lowest point: Idaho's lowest point is Snake River at 718 feet; Pennsylvania's is Delaware River at 0 feet. Pennsylvania's lowest point is 718 feet lower.
Idaho vs Pennsylvania Population and History
Population: Idaho has a population of 2,001,619 (2024), while Pennsylvania has 13,078,751 (2024). Pennsylvania's population is 6.5 times (553%) larger than Idaho's.
Population density: Idaho: 24.2 people per square mile vs Pennsylvania: 292.3. Pennsylvania's population density is 12.1 times higher than Idaho's.
Biggest city: Idaho's biggest city is Boise with 237,963 people; Pennsylvania's is Philadelphia with 1,573,916. Philadelphia's population is 6.6 times (561%) larger than Boise's.
Largest metro area: Idaho's largest metropolitan area is Boise City, ID metro area (845,877 people) vs Pennsylvania's Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metro area (6,330,422). Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metro area's population is 7.5 times (648%) larger than Boise City, ID metro area's.
History: Idaho: Admitted to the Union on July 3, 1890, as the 43rd state. Pennsylvania: Admitted to the Union on December 12, 1787, as the 2nd state. In its current form, Pennsylvania is the older of the two by 103 years.
Idaho vs Pennsylvania Economy
GDP: Idaho's GDP is $129.0 billion (2024) vs Pennsylvania's $1,007.9 billion. Pennsylvania's economic output is 7.8 times (681%) larger than Idaho's.
GDP per capita: Idaho: $64,457 per person vs Pennsylvania: $77,062. Pennsylvania's GDP per capita is 1.2 times (20%) higher than Idaho's.
Average income: Idaho: $62,323 vs Pennsylvania: $70,678 average income per person (per capita personal income). Pennsylvania's average income is 1.1 times (13%) higher than Idaho's.
Idaho vs Pennsylvania Counties
Number of counties: Idaho has 44 counties, while Pennsylvania has 67. Pennsylvania's county count is 1.5 times (52%) higher than Idaho's.
Biggest county by area: Idaho's largest county is Idaho County at 8,478 square miles; Pennsylvania's is Lycoming County at 1,229 square miles. Idaho County's land area is 6.9 times (590%) larger than Lycoming County's.
Smallest county by area: Idaho: Payette County (407 sq mi) vs Pennsylvania: Montour County (130 sq mi). Payette County's land area is 3.1 times (212%) larger than Montour County's.
Most populous county: Idaho: Ada County (535,799 people) vs Pennsylvania: Philadelphia County (1,573,916 people). Philadelphia County's population is 2.9 times (194%) larger than Ada County's.
Least populous county: Idaho: Clark County (794 people) vs Pennsylvania: Cameron County (4,348 people). Cameron County's population is 5.5 times (448%) larger than Clark County's.
Richest county: Idaho: Blaine County ($202,612 per capita income) vs Pennsylvania: Chester County ($110,883). Blaine County's income is 1.8 times (83%) richer than Chester County's.
Poorest county: Idaho: Madison County ($29,485 per capita income) vs Pennsylvania: Forest County ($30,234). Madison County and Forest County have about the same income.
Idaho vs Pennsylvania Taxes
State income tax: Idaho has a top income tax rate of 5.3%, while Pennsylvania has a top income tax rate of 3.07%. Idaho's top rate is 2.23 percentage points higher.
Property tax: Idaho: 0.43% effective rate vs Pennsylvania: 1.16% of home value per year. Pennsylvania's rate is 0.73 percentage points higher.
Sales tax: Idaho: 6.03% combined state and average local rate vs Pennsylvania: 6.34%. Pennsylvania's combined rate is 0.31 percentage points higher.
Official Websites
Idaho official website · Pennsylvania official website
More Size Comparisons
All Idaho size comparisons · All Pennsylvania 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.