| True area | On the old Mercator map | Distortion vs truth |
|---|
| El Salvador | 20,401 km² | 21,625 km² | 1.1× |
| Greenland | 2,154,754 km² | 25,447,645 km² | 11.8× |
| Africa | 30,370,000 km² | — | 1× |
Old maps drew El Salvador at about 21,625 km² km². The truth is 20,401 km² km² — a difference of 6%% that school atlases carried for centuries.