2QUESTION 2 OF 3
Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
770
iPhones
How to estimate it
Fermi’s official “Napkin math”
The easiest place to start is Apple itself, which brings in around $400 billion a year. How much of that is iPhones? Maybe half. And an iPhone costs about $1,000.
- Apple's yearly sales
- ~$400B
- Half from iPhones
- ≈ $200B
- ÷ $1,000 a phone
- ≈ 200M a year
- 200M ÷ 31.5M seconds, × 100
- ≈ 630
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- iPhones shipped in 2025 (IDC 247.8M, Omdia 240.6M)
- ≈ 244,000,000
- Seconds in a year
- ÷ 31,536,000
- iPhones a second
- ≈ 7.7
- × 100 seconds
- ≈ 770
Reference cited by Fermi: IDC and Omdia smartphone trackers: about 241 to 248 million iPhones shipped in 2025
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.