How to play

One sheet, five rounds, no numbers until you lock in: just your eye.

1. Look at the reference

The hatched object is drawn to scale. Its size never changes: it's your yardstick.

Dimension lines show which measurement counts: height, length, diameter or span.

On a phone: drag up to grow, down to shrink. You can also pinch.
With a mouse: drag on the sheet or use the wheel.
With a keyboard: focus the slider, then arrows (±1%) or Shift + arrows (±10%).
The camera reframes by itself when the object leaves the frame. Use "Reframe" if needed.

The real silhouette appears in green dashes with its exact dimension, along with what other players guessed.

Each round is worth up to 100 points. Within 5% you get 100: spot on. The score then drops steadily and reaches 0 when you're off by a factor of 5.

Guessing half or double costs exactly the same: ×2 and ÷2 score equally.

A new sheet arrives at midnight (Paris time), the same for everyone. Come back daily to grow your streak, and challenge friends on the same sheet.