Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
62
rinks
How to estimate it
Fermi’s official “Napkin math”
An Olympic pool is about 7 feet deep, so 84 one-inch layers of water. How big is a pool next to a rink? About 160 by 80 feet against 200 by 85, so call it three quarters of a rink.
- Pool depth, ~7 ft
- 84 layers of 1 in
- Pool floor vs rink floor
- × 3/4
- 84 × 3/4
- ≈ 63 rinks
An Olympic pool is 2 meters deep, which is 80 layers of 2.5 cm. How big is a pool next to a rink? A pool is 50 by 25 meters. A rink is a bit longer, maybe 60 by 25.
- 200 cm ÷ 2.5 cm
- 80 layers
- Pool floor, 50 × 25
- 1,250 m²
- Rink floor, 60 × 25
- ÷ 1,500 m²
- 80 × 1,250 ÷ 1,500
- ≈ 67 rinks
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Olympic pool, 50 m × 25 m × 2 m deep
- 2,500,000 liters
- Water to make one NHL ice sheet, 10,600 gallons (Science of NHL Hockey)
- ÷ 40,000 liters
- 2,500,000 ÷ 40,000
- ≈ 62 rinks
Reference cited by Fermi: Science of NHL Hockey (NBC Learn with the National Science Foundation and the NHL): about 10,600 gallons (40,000 liters) of water per NHL ice sheet · Olympic-size pool of 2,500,000 liters (50 × 25 m, 2 m deep)
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