Is the shape always a circle?

On easy levels, yes. Harder modes introduce shapes where width and height are separate (rectangles, ellipses), requiring you to remember two dimensions independently.

What percentage error is excellent?

Under 5% is excellent. Under 10% is solid. Most players hit 15–20% error without practice.

Does shape position affect size memory?

Research shows objects near the periphery of vision are judged as slightly smaller than they are. Centrally-placed shapes are easier to size-match accurately.

Can You Match the Scale?

Can you match the scale of an object after seeing it flash briefly? A circle (or shape) appears at a specific size for 1.5 seconds, then disappears. A resizable version appears and you drag to make it match. Your score is the percentage error between your reproduced size and the original. Size memory turns out to be surprisingly noisy — most people over-shrink large shapes and over-inflate small ones.

How to Play

A shape appears at a specific size for about 1.5 seconds.
The shape disappears and a resizable version appears in its place.
Drag the handle to resize it to match the remembered size.
Your error as a percentage of the original size is shown.

Why It's Hard

Size memory is subject to regression to the mean — when uncertain, your brain defaults to "medium." Unusually large shapes are remembered as smaller than they were, and unusually small shapes are remembered as larger. This compression effect, combined with the absence of a reference during reproduction, means size errors of 15–25% are typical without practice.

Tips

1Note the shape's size relative to the canvas edges — "it was about 1/3 of the canvas width."
2Start larger than you think and scale down — overshoot-and-correct is more accurate than building up from nothing.
3For circles, the diameter is more memorable than the radius — think in diameter when encoding.

FAQ

Is the shape always a circle?: On easy levels, yes. Harder modes introduce shapes where width and height are separate (rectangles, ellipses), requiring you to remember two dimensions independently.
What percentage error is excellent?: Under 5% is excellent. Under 10% is solid. Most players hit 15–20% error without practice.
Does shape position affect size memory?: Research shows objects near the periphery of vision are judged as slightly smaller than they are. Centrally-placed shapes are easier to size-match accurately.

Built by

Ethan R. Caldwell

Game Developer · Wilmington, DE

Designed Can You Match the Scale? and 46 other browser puzzles. Game developer based in Wilmington, Delaware. Hardcore puzzle gamer at heart — obsessed with logic puzzles, sokoban-style mechanics, and physics-based brain teasers. Off the clock, unwinds with ARPGs, RPGs and JRPGs.

[email protected]