3QUESTION 3 OF 3
Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
370,000,000
books
How to estimate it
Fermi’s official “Napkin math”
There's no clean anchor for Amazon's own book count. Start with US adults, about 260,000,000. How many buy at least one print book from Amazon this year? Call it 1 in 3, and maybe 3 books each.
- US adults
- 260,000,000
- Buy an Amazon print book this year (guess)
- 1 in 3
- Average books bought per buyer (guess)
- × 3
- 260M ÷ 3 × 3
- ≈ 260,000,000
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Total US print book units sold, 2024 (Circana BookScan, tracks ~85% of market)
- 782,700,000
- Estimated full market (scaled up for BookScan's ~85% coverage)
- ≈ 920,000,000
- Amazon's estimated share of US print book sales
- × ≈ 40%
- Estimated Amazon print books sold
- ≈ 370,000,000
Reference cited by Fermi: Circana BookScan 2024 US print unit sales, combined with industry estimates of Amazon's share of the US print book market
How close was your guess?
Your comparison will appear here.
Compare by ratio: divide the larger number by the smaller one. The closer to 1×, the better.