2QUESTION 2 OF 3
Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
16,000
passengers
How to estimate it
Fermi’s official “Napkin math”
Heathrow is England's largest airport so let's figure it moves a plane about every minute, that's 1,300 flights a day with ~180 people on each. How long is one passenger actually inside the building? Departing people turn up early and arriving people walk straight out, so ~1.5 hours each.
- Flights per day
- ≈ 1,300
- People per flight
- × 180
- Hours inside the terminal
- × 1.5
- 234,000 × 1.5 ÷ 24
- ≈ 15,000
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Heathrow passengers in 2025, a record year (Heathrow's own figure)
- 84.5 million
- ÷ 365 days
- ≈ 231,000 per day
- Average time inside the terminal (departing about 2.5 hours, arriving under one)
- ≈ 1.7 hours
- 231,000 × 1.7 ÷ 24 hours
- ≈ 16,000
Reference cited by Fermi: Heathrow Airport 2025 annual passenger and air transport movement figures
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