Closer than most people guess: Sudan (1,878,000 km²) is only about 7% larger than Libya (1,759,540 km²).
Both sit in Africa, so this is a same-region comparison: the new Equal Earth map draws both with the same honest geometry, and the real gap is exactly the 1.1× you see above.
The old Mercator map treated both about equally (1.3× vs 1.1× inflation), so at least their relative sizes were preserved, even if both were drawn at the wrong absolute scale.
Libya fits 1× into Sudan.
Libya vs Sudan: key figures
| Measure | Libya | Sudan |
|---|
| True area | 1,759,540 km² · #17 | 1,878,000 km² · #16 |
| Mercator inflation | 1.3× | 1.1× |
| Apparent on Mercator | 2,217,020 km² | 2,031,808 km² |