Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
24,700,000
M&M's
How to estimate it
Fermi’s official “Napkin math”
The Boston Marathon fields about 30,000 runners a year. Running 26 miles burns a lot of energy, maybe 3,000 calories a person. One M&M is basically nothing, worth about 3 calories.
- Boston Marathon runners
- ~30,000
- Calories burned each
- × 3,000
- 90 million ÷ 3 cal per M&M
- ≈ 30 million M&M's
The Boston Marathon fields about 30,000 runners a year. Running 42 kilometers burns a lot of energy, maybe 3,000 calories a person. One M&M is basically nothing, worth about 3 calories.
- Boston Marathon runners
- ~30,000
- Calories burned each
- × 3,000
- 90 million ÷ 3 cal per M&M
- ≈ 30 million M&M's
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Boston Marathon field size (BAA)
- ≈ 30,000 runners
- Avg. calories burned per marathon
- × 2,800 kcal
- Total calories burned by the field
- ≈ 84,000,000 kcal
- ÷ calories per M&M (3.4 kcal)
- ≈ 24.7 million M&M's
Reference cited by Fermi: Boston Athletic Association official field size (~30,000 entrants, capped field); marathon calorie-burn estimates from sports-science consensus (~100 kcal per mile of running); Mars Wrigley nutrition facts for M&M'S Milk Chocolate (148 cal per 43 pieces ≈ 3.4 cal/piece).
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