All Fermi answers
Fermi #27 · Question 3

How many Vatican Cities would fit inside Manhattan Island?

Explore the official answer and the simple reasoning behind this Fermi estimate.

3QUESTION 3 OF 3

Answer & explanation

The official answer, with Fermi’s reasoning step by step.

Answer & explanation

Official answer

130

Vatican Cities

How to estimate it

Fermi’s official “Napkin math”

The Vatican is a walled patch inside Rome, roughly 700 meters across, so about half a square kilometer. How big is Manhattan? A long thin island, something like 21 kilometers by 3, call it 60 square kilometers.

Manhattan Island
~60 km²
Vatican City
÷ 0.5 km²
60 ÷ 0.5
≈ 120

Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.

Source calculation & reference
Manhattan Island area
22.7 sq mi (58.8 km²)
Vatican City area
0.17 sq mi (0.44 km²)
58.8 ÷ 0.44
≈ 130

Reference cited by Fermi: Vatican City State official website and CIA World Factbook (Vatican City area, 0.44 km²) · Manhattan Island area, 22.7 sq mi

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