Fermi question · Science
About how many kilometers is the Moon from Earth on average?
Make a fast, defensible estimate before you reveal the reference answer. Think in factors, not exact recall.
What is your estimate?
Your result will appear here after you submit a guess.
Reference answer
Reveal the reference answer
≈ 384 thousand kilometers
Fermi estimates are judged by scale, so a reasonable approximation can still earn a strong score.
One way to estimate it
Use the familiar rule of thumb that roughly 30 Earth diameters fit between Earth and the Moon.
- Earth diameter≈ 12,800 km
- Earth diameters to Moon≈ 30
- Estimate12,800 × 30 ≈ 384,000 km
Keep practicing
Try another question, or return to the daily challenge to build your personal sense of scale.