Guess It Size — The Daily Size Guessing Game
Can you really see how big things are?
One reference drawn to scale, one object to size by eye, no numbers until you lock it in.
Three moves
- 01
Compare
The hatched reference is drawn to the right scale.
- 02
Size
Drag up or down to grow or shrink the orange object.
- 03
Lock in
The true size appears. Up to 100 points per round.
Still want to measure?
Random pairs, no limit, to sharpen your eye between sheets.
Start practisingFAQ
Do I need an account?
No. Your progress, streak and stats stay on your device.
Why no numbers during a round?
So your eye does the comparing, not arithmetic. Values appear as soon as you lock in.
Is the game the same for everyone?
Yes: one sheet a day, identical for all, renewed at midnight Paris time.
How do I challenge a friend?
At the end of a game, create a challenge link. Your friend plays the same sheet and sees your estimates after each round.
What if I want to keep playing?
Practice mode offers random pairs with no limit, without touching your streak.
Does the game collect my data?
No. There is no account, no database and nothing kept on the server: your progress stays in your browser.
Are there ads?
Not for now. If ads ever appear, a consent window will come first, and they will never sit next to the game's buttons.
About this game
What Guess It Size is
Guess It Size is a daily size guessing game. Every day at midnight Paris time, everyone gets the same sheet: five rounds, five objects to judge. One object is drawn to scale and named — a wine bottle, a horse, a TGV trainset. The other is the one you have to size, and it deliberately starts wrong.
Nothing to install, no account to create. A game takes about two minutes.
How a round works
You grow or shrink the orange shape until it looks right next to the reference: drag up to enlarge, down to reduce, or pinch on a phone. No number appears while you decide — that is the whole point. Your eye does the comparing, not a calculator.
When you lock in, the true size appears and you score up to 100 points. Within 5% scores 100; a factor of five off scores 0. Five rounds make 500 points.
Why it is harder than it looks
Our sense of size is logarithmic and depends enormously on context. We judge well what we handle every day, and badly everything else: what is very large, very small, or only ever seen in photographs.
Hence pairs that cross categories — a giraffe against a wine bottle, a container ship against a horse. The surprise is the reward, and after a few days your estimates tighten.
It is a visual size estimation game, not a quiz: nothing to look up, nothing to calculate — only what your eye can judge.
Where the measurements come from
Every size has a definition and a source. "A giraffe is 5 m" means nothing on its own: each object states what is measured — total height, length, diameter, wingspan — and points to the source the value came from.
The Credits page lists all 155 objects with their source and status: measured directly in the source, or taken from a cited reference and still to be double-checked. Sizes vary in real life; the game uses a typical adult specimen unless stated otherwise.