Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
2,700
chickens
How to estimate it
Fermi’s official “Napkin math”
A T. rex weighed about as much as a large elephant, call it 8 tons, which is 16,000 pounds. How much does a chicken weigh? You can carry one under your arm, so maybe 5 pounds. Divide one by the other.
- Adult T. rex
- ≈ 16,000 lbs
- One chicken
- ≈ 5 lbs
- 16,000 ÷ 5
- ≈ 3,200
A T. rex weighed about as much as a large elephant, call it 8 tonnes, so 8,000 kilograms. How much does a chicken weigh? You can carry one under your arm, so maybe 2.5 kilograms. Divide one by the other.
- Adult T. rex
- ≈ 8,000 kg
- One chicken
- ≈ 2.5 kg
- 8,000 ÷ 2.5
- ≈ 3,200
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Adult T. rex body mass (modern estimates cluster at 6,000–9,000 kg)
- ≈ 8,000 kg
- Average live weight of a chicken at market (National Chicken Council)
- ≈ 6.5 lbs, so 3 kg
- 8,000 ÷ 3
- ≈ 2,700
Reference cited by Fermi: National Chicken Council broiler market-weight statistics; T. rex mass from Encyclopedia Britannica
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