| U.S. State / Size (sq km) | Twin Country | Larger 'Twin' / Size Difference (sq km) |
| Alaska / 1,717,854 | |
| Texas / 695,621 | |
| California / 423,970 | |
| Montana / 380,838 | |
| New Mexico / 314,915 | |
| Arizona / 295,254 | |
| Nevada / 286,351 | |
| Colorado / 269,601 | |
| Oregon / 254,805 | |
| Wyoming / 253,336 | |
| Michigan / 250,494 | |
| Minnesota / 225,171 | |
| Utah / 219,887 | |
| Idaho / 216,446 | |
| Kansas / 213,096 | |
| Nebraska / 200,345 | |
| South Dakota / 199,731 | |
| Washington / 184,665 | |
| North Dakota / 183,112 | |
| Oklahoma / 181,035 | |
| Missouri / 180,533 | |
| Florida / 170,304 | |
| Wisconsin / 169,639 | |
| Georgia / 153,909 | |
| Illinois / 149,998 | |
| Iowa / 145,743 | |
| | U.S. State / Size (sq km) | Twin Country | Larger 'Twin' / Size Difference (sq km) |
| New York / 141,299 | |
| North Carolina / 139,389 | |
| Arkansas / 137,732 | |
| Alabama / 135,765 | |
| Louisiana / 134,264 | |
| Mississippi / 125,434 | |
| Pennsylvania / 119,283 | |
| Ohio / 116,096 | |
| Virginia / 110,785 | |
| Tennessee / 109,151 | |
| Kentucky / 104,659 | |
| Indiana / 94,321 | |
| Maine / 91,646 | |
| South Carolina / 82,932 | |
| West Virginia / 62,755 | |
| Maryland / 32,133 | |
| Hawaii / 28,311 | |
| Massachusetts / 27,336 | |
| Vermont / 24,901 | |
| New Hampshire / 24,216 | |
| New Jersey / 22,588 | |
| Connecticut / 14,357 | |
| Delaware / 6,447 | |
| Rhode Island / 4,002 | |
| District of Columbia / 176.75 | |
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