Estimania

About Estimania

Estimania asks you to guess numbers rather than recall facts. Every day at midnight UTC a new set of five questions appears, spanning science, geography, history, sport and more. Some are Fermi questions in the spirit of the physicist's back-of-the-envelope problems, such as how many piano tuners work in Chicago, where nobody knows the exact answer but reasoning gets you close.

Each answer scores from 0 to 100 points based only on the ratio between your guess and the true value: points = 100 times (1 minus the absolute base-10 log of guess divided by answer). A perfect guess scores 100, being off by a factor of 2 scores 70, and being off by a factor of 10 or more scores nothing. Guessing too high and too low by the same factor costs the same.

After five questions you see your total out of 500 and where you rank on the day's leaderboard, then share your score. No sign-up is needed, and players can submit their own question ideas.

It suits Fermi problem fans, quiz players who like reasoning over memory, and anyone who wants to train a feel for scale.

How to play Estimania

1. Read the question; every answer is a number.
2. Type your best estimate and submit.
3. Score up to 100 points depending on how close you are on a logarithmic scale.
4. After five questions see your total out of 500, your leaderboard rank, and share.

Tips

• Break hard questions into smaller estimates you can multiply (people times rate times time).
• Think in powers of ten first, then refine the leading digit.
• Because scoring is by ratio, an answer between two plausible values is often safest.
• Do not leave silly round guesses; a factor of 10 off scores zero.

Questions