| Country | Area - comparative |
| Italy | slightly larger than Arizona |
| Jamaica | slightly smaller than Connecticut |
| Jan Mayen | slightly more than twice the size of Washington, DC |
| Japan | slightly smaller than California |
| Jersey | about two-thirds the size of Washington, DC |
| Jordan | slightly smaller than Indiana |
| Kazakhstan | slightly less than four times the size of Texas |
| Kenya | slightly more than twice the size of Nevada |
| Kiribati | four times the size of Washington, DC |
| Korea, North | slightly smaller than Mississippi |
| Korea, South | slightly larger than Indiana |
| Kosovo | slightly larger than Delaware |
| Kuwait | slightly smaller than New Jersey |
| Kyrgyzstan | slightly smaller than South Dakota |
| Laos | slightly larger than Utah |
| Latvia | slightly larger than West Virginia |
| Lebanon | about 0.7 times the size of Connecticut |
| Lesotho | slightly smaller than Maryland |
| Liberia | slightly larger than Tennessee |
| Libya | slightly larger than Alaska |
| Liechtenstein | about 0.9 times the size of Washington, DC |
| Lithuania | slightly larger than West Virginia |
| Luxembourg | slightly smaller than Rhode Island |
| Macau | less than one-sixth the size of Washington, DC |
| Macedonia | slightly larger than Vermont |
| Madagascar | slightly less than twice the size of Arizona |