Greenland is clearly the larger of the two: about 2,166,086 km² against 1,564,116 km², roughly 1.4× at true size. Drag one onto the other on the map above to feel the gap.
Greenland sits in North America, Mongolia in Asia. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 1.4×.
The old map muddied it further: Mercator inflates Greenland about 11.8× and Mongolia about 2.1×, so on a Mercator-style map this pair appears 7.6× apart instead of the true 1.4×.
Mongolia fits 1× into Greenland.
Greenland vs Mongolia: key figures
| Measure | Greenland | Mongolia |
|---|
| True area | 2,166,086 km² · #12 | 1,564,116 km² · #19 |
| Mercator inflation | 11.8× | 2.1× |
| Apparent on Mercator | 25,576,494 km² | 3,357,375 km² |