Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
29,000
ears
How to estimate it
Fermi’s official “Napkin math”
An acre is about 44,000 square feet. Corn rows sit about 2.5 feet apart. How close are the stalks in a row? Maybe 6 inches, so each stalk gets a bit over a square foot and grows one ear.
- One acre
- 44,000 sq ft
- 2.5 ft × 0.5 ft per stalk
- ÷ 1.25 sq ft
- 44,000 ÷ 1.25
- ≈ 35,000
A hectare is 10,000 square meters, so 0.4 is 4,000. Corn rows sit about 75 cm apart. How close are the stalks in a row? Maybe 15 cm, which fits about 9 in a square meter, with one ear each.
- 0.4 hectare
- 4,000 m²
- Stalks per square meter
- × 9
- 4,000 × 9
- ≈ 36,000
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- USDA NASS ear counts, 10 States, 2025 final
- 28,550 per acre
- Same survey, October 2026
- 28,600 per acre
- Plants per acre, 2025 final, about 1 ear each
- 28,800
- ≈
- 29,000
Reference cited by Fermi: USDA NASS Crop Production, objective yield survey: 28,550 ears per acre (10 States, 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.