All Fermi answers
Fermi #7 · Question 1

How tall would a stack of 1 million $1 bills be?

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

1QUESTION 1 OF 3

Answer & explanation

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

Answer & explanation

Official answer

358

feet

How to estimate it

Fermi’s official “Napkin math”

How thick is a single bill? Really thin, maybe a tenth of a millimeter. Stack a million of them and it adds up fast.

Bill thickness
~0.1 mm
× 1,000,000 bills
= 100 m
In feet
≈ 350 ft

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

Source calculation & reference
Thickness of one bill
≈ 0.0043 in
1,000,000 × 0.0043
= 4,300 in
Convert to ft
÷ 12 ≈ 358

Reference cited by Fermi: U.S. Bureau of Engraving & Printing

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