Overview
Fermi Questions test your estimation skills with order-of-magnitude questions. As a trader you work with a lot of different numbers, so estimating quickly helps you recognise when something is off. Each round gives you a question with a numeric answer, either a fact (a real, lookup-able number like a population or a distance) or a guesstimate (no single right answer, built up from first principles). You break the problem into pieces you can reason about, enter your best estimate before the timer runs out, and the closer you land on a log scale, the more points you score.
Example: one estimation round
Each round puts one question on screen with a badge telling you whether it is a fact or a guesstimate. You break it down, type a single number and submit before the clock runs out. The real answer and a short explanation on how you could have estimated it follow on the next screen.
Example animation
Time remaining
38s37s36s35s34s33s32s31s30s29s28s27s26s25s24s23s
Guesstimate
How many pizzas are consumed in the US each day?
▶ Unit conversions
Your Estimate
60,000,000
Submit
Next question in
25s24s23s22s21s20s19s18s17s16s15s14s13s12s11s10s
Guesstimate
How many pizzas are consumed in the US each day?
Correct Answer
8,400,000
Roughly 8.4 million pizzas are eaten in the US each day. A top-down 95% confidence interval:
• US population
~340M, 335–345M range • Pizza meals per person per month, how often someone sits down to pizza
~2, 1–4 range • Whole pizzas eaten per meal, a few slices of a shared pie ≈ a third
~1/3, 1/4–1/2 range • Days per month, converting the monthly total to a daily rate
÷30.4, fixed Multiplied range: • Low: 335M × 1 × 1/4 ÷ 30.4 ≈ 2.8M • High: 345M × 4 × 1/2 ÷ 30.4 ≈ 23M • Central: 340M × 2 × 1/3 ÷ 30.4 ≈ 7.5M Sources: US population ~340M (US Census Bureau, 2024); ~3 billion pizzas sold per year ≈ 8M/day (industry estimates).
~340M, 335–345M range • Pizza meals per person per month, how often someone sits down to pizza
~2, 1–4 range • Whole pizzas eaten per meal, a few slices of a shared pie ≈ a third
~1/3, 1/4–1/2 range • Days per month, converting the monthly total to a daily rate
÷30.4, fixed Multiplied range: • Low: 335M × 1 × 1/4 ÷ 30.4 ≈ 2.8M • High: 345M × 4 × 1/2 ÷ 30.4 ≈ 23M • Central: 340M × 2 × 1/3 ÷ 30.4 ≈ 7.5M Sources: US population ~340M (US Census Bureau, 2024); ~3 billion pizzas sold per year ≈ 8M/day (industry estimates).
All Answers
Player
Answer
Factor
Points
You
60,000,000
7.1x
4
Scoring runs on a log scale, so the order of magnitude matters far more than the leading digit.
This is a looping illustration of the game screen, not the live game.
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Game Phases
1
Read the question
Each round shows a question with a numeric answer. A badge marks it as a fact (a real, lookup-able number) or a guesstimate (something you estimate from first principles).
2
Break it down
Do not try to recall the number. Split the problem top-down into pieces you can reason about, then multiply back up. Think in orders of magnitude first, then refine.
3
Estimate before the timer
Type your best positive number and submit to lock it in. Each round has a time limit (60 seconds by default) and you cannot change an answer once it is submitted.
4
Learn from the reveal
The real answer and a short explanation appear after you submit. Compare it to your reasoning to see where your estimate drifted, then close that gap next round.
Scoring
+10
Closer is better
Points scale by how many times off you are, not the raw difference. Within about 12 percent scores the full 10; within 2x scores 4; anything within 10x still scores at least 1.
0
Way off
More than 10x away from the answer scores nothing for that round.
-2
No answer
Always submit something. Leaving a round blank costs you 2 points.
0
Tab switch
Switching tabs to look things up forfeits the round and scores 0.
Factor
Your consistency
Solo play also tracks your average factor off, the typical multiplier your estimates miss by. Lower is better, and 1x is perfect.
Your score is the sum of points across every round, so more rounds allow a higher total. Because scoring runs on a log scale, getting the right order of magnitude matters far more than the leading digit. There is no leaderboard for Fermi Questions. Instead your progress is tracked by your average factor off over time, so you can watch your estimates get sharper.
Your progress
📊 Track your progress
See your scores over time and watch yourself improve.
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