Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
7,600
kilometers
How to estimate it
Fermi’s official “Napkin math”
Italy's boot is about 1,200 kilometres long, and it has coast down both sides. That is already 2,400. Then add Sicily, Sardinia and every bay and headland, which easily triples it.
- Length of the boot
- ~1,200 km
- Coast on both sides
- × 2
- Islands and all the wiggles
- × 3
- 1,200 × 2 × 3
- ≈ 7,200 km
Italy's boot is about 750 miles long, and it has coast down both sides. That is 1,500. Then add Sicily, Sardinia and every bay and headland, which easily triples it.
- Length of the boot
- ~750 mi
- Coast on both sides
- × 2
- Islands and all the wiggles
- × 3
- 750 × 2 × 3
- ≈ 4,500 mi
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Mainland and island coastline (World Factbook)
- = 7,600 km
- Same figure in miles
- ≈ 4,700 miles
- Islands included
- 3,766 of them
Reference cited by Fermi: CIA World Factbook coastline figures
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