Greenland is clearly the larger of the two: about 2,166,086 km² against 1,285,216 km², roughly 1.7× at true size. Drag one onto the other on the map above to feel the gap.
Greenland sits in North America, Peru in South America. On the old Mercator map the latitude gap distorted how large each felt beside the other; at true size the answer is simply 1.7×.
The old map muddied it further: Mercator inflates Greenland about 11.8× and Peru about 1.03×, so on a Mercator-style map this pair appears 19.4× apart instead of the true 1.7×.
Peru fits 1× into Greenland.
Greenland vs Peru: key figures
| Measure | Greenland | Peru |
|---|
| True area | 2,166,086 km² · #12 | 1,285,216 km² · #20 |
| Mercator inflation | 11.8× | 1.03× |
| Apparent on Mercator | 25,576,494 km² | 1,318,246 km² |