Arctic Ocean:
slightly less than 1.5 times the size of the US

Argentina:
slightly less than three-tenths the size of the US

Armenia:
slightly smaller than Maryland

Aruba:
slightly larger than Washington, DC

Ashmore and Cartier Islands: about eight times the size of The Mall in Washington, DC

Atlantic Ocean:
slightly less than 6.5 times the size of the US

Australia:
slightly smaller than the contiguous 48 states of the US

Austria:
slightly smaller than Maine

Azerbaijan:
slightly smaller than Maine

Bahamas, The:
slightly smaller than Connecticut