How close can you guess?
A free daily estimation game — five numerical trivia questions every day, no sign-up needed.
Estimania is the free daily estimation game for curious minds. Every day brings five new questions with a numerical answer, drawn from all corners of knowledge. Your job is to guess as close as you can. You don't need to know the exact number: a good estimate is enough, and every answer comes with a short explanation, so you learn something about the world in a playful way. Then share your score with your friends, and come back for a new puzzle at midnight UTC.
Depends on your browser. On mobile:
Chrome: Tap the three dots (⋮) in the top-right corner → “Translate”.
Safari: Tap “AA” or the page icon in the address bar → “Translate”.
No topic is excluded! Questions span science, geography, history, sport, and more — always with a numerical answer. Some are deliberately Fermi questions: named after physicist Enrico Fermi, these are back-of-the-envelope estimation challenges where the exact answer is hard to know but a reasonable ballpark can be reached through logical reasoning (e.g. "How many piano tuners are in Chicago?"). You are not expected to know the answer — you are expected to think it through. You can also submit a question suggestion here.
Only the ratio between your guess and the answer counts, not the difference. Being 2× off scores the same whether the answer is 5 or 5 billion. A perfect guess scores 100, and being off by a factor of 10 (or more) scores 0. Guessing too high and too low by the same factor cost the same.
For example, if the answer is 100:
| Your guess | Off by | Points |
|---|---|---|
| 110 or 90.9 | 1.1× | 96 |
| 120 or 83.3 | 1.2× | 92 |
| 150 or 66.7 | 1.5× | 82 |
| 200 or 50 | 2× | 70 |
| 300 or 33.3 | 3× | 52 |
| 500 or 20 | 5× | 30 |
| 1000 or 10 | 10× | 0 |
For the curious:
points = 100 × (1 − |log₁₀(guess ÷ answer)|)
Percentage questions use a different formula. The answer can never go above 100%, so the usual ratio would be far too generous: if the answer is 90%, a guess of 80% is only 1.1× off and would still score 95. These questions are scored on the odds instead (90% means 90 to 10), which makes them stricter. The same 80% guess scores 65.
points = 100 × (1 − |log₁₀(guess ÷ (100 − guess)) − log₁₀(answer ÷ (100 − answer))|)
Some questions are scored more strictly, because their answer can only fall within a narrow range (for example, the age of the oldest person ever). On those, being off by 3× already scores 0. If the answer is 100, a guess of 125 scores 80 and a guess of 150 scores 63.
points = 100 × (1 − |log₁₀(guess ÷ answer)| ÷ log₁₀(3))
Not at all. Many questions — like "How many dogs exist worldwide?" — don't have a single exact answer. The point of the game is to develop a reasonable sense of scale, not to recall a precise figure. The reference answer is sourced from a credible estimate, and the log-scale scoring means you're rewarded generously for being in the right ballpark. Getting the order of magnitude right is the goal.
A new puzzle is released every day at midnight UTC. Once you complete a puzzle, it locks — each puzzle can only be played once.
Yes. After completing your first puzzle you can generate a recovery code to link a second device, so your scores and leaderboard rank stay in sync.
Only if you both want that. In a friend group, tapping a name on the day's leaderboard shows their score per question. The actual guesses stay hidden unless both of you have turned on “Share my guesses” on your settings page. Nobody outside your groups can ever see them.
Lost that device too? Then start fresh: delete the browser data for this site and when you play next time, you can enter a new nickname. If you're on the App:
Android: Settings → Apps → Estimania → Storage → Clear Data (resets everything)
iOS: Deleting and reinstalling the PWA is the only option
Sort of — you can add Estimania to your home screen. It’s not an app-store download, just a shortcut to this website that opens full-screen. On Android, use “Add to Home screen” in Chrome’s menu; on iOS, use “Add to Home Screen” in Safari’s share menu.
Estimania is developed by me, Valentin. I am a 27 year old solo developer and trivia geek based in Graz, Austria. If you want to reach out, you can via Instagram or this form.
Currently, it doesn't - it's a pure passion project. If you want to help with the associated costs, you can support the project on Ko-fi.