The map above shows Arizona and Idaho side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Arizona vs Idaho Geography
Land area: Arizona has a land area of 113,655 square miles (294,366 km²), while Idaho has 82,645 square miles (214,051 km²). Arizona's land area is 1.4 times (38%) larger than Idaho's.
Total area: Arizona: 113,985 square miles (295,220 km²) vs Idaho: 83,569 square miles (216,441 km²), including inland and coastal water. Arizona's total area is 1.4 times (36%) larger than Idaho's.
Length: Arizona is 429 miles (690 km) long from north to south; Idaho is 483 miles (778 km). Idaho's north-south length is 1.1 times (13%) longer than Arizona's.
Width: Arizona spans 452 miles (727 km) east to west; Idaho spans 352 miles (566 km). Arizona's east-west width is 1.3 times (28%) wider than Idaho's.
Highest point: Arizona's highest point is Humphreys Peak at 12,620 feet (3,847 m); Idaho's is Borah Peak at 12,631 feet (3,850 m). Borah Peak is 11 feet higher than Humphreys Peak.
Lowest point: Arizona's lowest point is Colorado River at 71 feet; Idaho's is Snake River at 718 feet. Arizona's lowest point is 647 feet lower.
Arizona vs Idaho Population and History
Population: Arizona has a population of 7,582,384 (2024), while Idaho has 2,001,619 (2024). Arizona's population is 3.8 times (279%) larger than Idaho's.
Population density: Arizona: 66.7 people per square mile vs Idaho: 24.2. Arizona's population density is 2.8 times (176%) higher than Idaho's.
Biggest city: Arizona's biggest city is Phoenix with 1,673,164 people; Idaho's is Boise with 237,963. Phoenix's population is 7.0 times (603%) larger than Boise's.
Largest metro area: Arizona's largest metropolitan area is Phoenix-Mesa-Chandler, AZ metro area (5,186,958 people) vs Idaho's Boise City, ID metro area (845,877). Phoenix-Mesa-Chandler, AZ metro area's population is 6.1 times (513%) larger than Boise City, ID metro area's.
History: Arizona: Admitted to the Union on February 14, 1912, as the 48th state. Idaho: Admitted to the Union on July 3, 1890, as the 43rd state. In its current form, Idaho is the older of the two by 22 years.
Arizona vs Idaho Economy
GDP: Arizona's GDP is $570.1 billion (2024) vs Idaho's $129.0 billion. Arizona's economic output is 4.4 times (342%) larger than Idaho's.
GDP per capita: Arizona: $75,186 per person vs Idaho: $64,457. Arizona's GDP per capita is 1.2 times (17%) higher than Idaho's.
Average income: Arizona: $65,798 vs Idaho: $62,323 average income per person (per capita personal income). Arizona's average income is 1.1 times (6%) higher than Idaho's.
Arizona vs Idaho Counties
Number of counties: Arizona has 15 counties, while Idaho has 44. Idaho's county count is 2.9 times (193%) higher than Arizona's.
Biggest county by area: Arizona's largest county is Coconino County at 18,616 square miles; Idaho's is Idaho County at 8,478 square miles. Coconino County's land area is 2.2 times (120%) larger than Idaho County's.
Smallest county by area: Arizona: Santa Cruz County (1,236 sq mi) vs Idaho: Payette County (407 sq mi). Santa Cruz County's land area is 3.0 times (204%) larger than Payette County's.
Most populous county: Arizona: Maricopa County (4,673,096 people) vs Idaho: Ada County (535,799 people). Maricopa County's population is 8.7 times (772%) larger than Ada County's.
Least populous county: Arizona: Greenlee County (9,410 people) vs Idaho: Clark County (794 people). Greenlee County's population is 11.9 times larger than Clark County's.
Richest county: Arizona: Maricopa County ($72,176 per capita income) vs Idaho: Blaine County ($202,612). Blaine County's income is 2.8 times (181%) richer than Maricopa County's.
Poorest county: Arizona: Graham County ($44,164 per capita income) vs Idaho: Madison County ($29,485). Graham County's income is 1.5 times (50%) richer than Madison County's.
Arizona vs Idaho Taxes
State income tax: Arizona has a top income tax rate of 2.5%, while Idaho has a top income tax rate of 5.3%. Idaho's top rate is 2.8 percentage points higher.
Property tax: Arizona: 0.43% effective rate vs Idaho: 0.43% of home value per year. The two are essentially equal.
Sales tax: Arizona: 8.54% combined state and average local rate vs Idaho: 6.03%. Arizona's combined rate is 2.51 percentage points higher.
Official Websites
Arizona official website · Idaho official website
More Size Comparisons
All Arizona size comparisons · All Idaho 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.