Size It Up

How to play Size It Up

1. Read the reference. The black silhouette is at real scale, and its measured dimension is labelled in metres — length for things that lie down, height for things that stand up.
2. Size the target. Drag anywhere on the board — the measured edge follows your pointer. Arrow keys move by 1/60 of the reference (⇧ is 1/400); the +/− buttons move by 1/12.
3. Lock it in. The red outline snaps out to the true size, your error is measured multiplicatively — so guessing half and guessing double cost exactly the same — and you get a score out of 100 plus one fact worth keeping.

Five rounds make a Daily, and the same five are served to every player on that date. Beyond that there is Unlimited mode, the animals and pop-culture pools, and challenge links that drop a friend straight into the same rounds you just played.

Why a size guessing game is harder than it sounds

Humans are bad at absolute scale and surprisingly good at relative scale. Show someone a school bus and ask for its length in metres and they will flounder; show them a bus next to a blue whale and they will confidently — and wrongly — tell you the whale is about twice as long. The error is systematic: we anchor on the familiar object and reason outward from there.

Size It Up makes that error visible. Because the target is resized rather than typed, the game measures your perception instead of your knowledge of trivia, and because scoring is multiplicative, overestimating and underestimating are punished identically. A 13% miss is a 13% miss, whichever direction you went.

Most players are within 30% on animals and wildly out on anything measured in metres rather than centimetres — buildings, whales and geological features are where the biggest mistakes live.

Tips that actually move your score

• Compare edges, not areas. Area scales with the square of length, so a shape that looks twice as big in area is only about 1.4× as long. Judge the shared measuring axis.
• Count reference-lengths. The black shape is the only ruler. Estimating "how many of those" is far easier than eyeballing metres.
• Pinch resizes. On a phone, two fingers scale the white shape. It changes your answer, the same as a drag.
• Trust the first read, then verify. Players who adjust for more than about 20 seconds usually overshoot.