Idaho has a land area of 82,645.1 square miles and a water area of 923.4 square miles. It is the 11th largest state by area.

Ada County, Idaho has 1,052.0 square miles of land area and is the 31st largest county in Idaho by total area.

Adams County, Idaho has 1,362.8 square miles of land area and is the 22nd largest county in Idaho by total area.

Bannock County, Idaho has 1,112.5 square miles of land area and is the 27th largest county in Idaho by total area.

Bear Lake County, Idaho has 975.7 square miles of land area and is the 32nd largest county in Idaho by total area.

Benewah County, Idaho has 776.9 square miles of land area and is the 34th largest county in Idaho by total area.

Bingham County, Idaho has 2,093.8 square miles of land area and is the 12th largest county in Idaho by total area.

Blaine County, Idaho has 2,637.7 square miles of land area and is the 7th largest county in Idaho by total area.

Boise County, Idaho has 1,899.6 square miles of land area and is the 14th largest county in Idaho by total area.

Bonner County, Idaho has 1,733.2 square miles of land area and is the 19th largest county in Idaho by total area.