Visual precision

1/5

Can you find the center of the circle?

Tap where you think the exact center is. A steel compass needle drops onto the board and measures your error in millimetres.

Clean circle A simple, finely drawn circle. No reference marks.

Tap the board or use the arrow keys and Enter.

Why do we place the center too high?

The human visual cortex does not calculate abstract Euclidean centroids. In natural environments, vision constantly surveys ground receding downward toward the horizon.

To compensate for this terrestrial perspective, the brain lifts the perceived center of two-dimensional shapes by 1.5% to 4.0% above the true geometric center. Most people tap the circle above the mathematical axis.

How we measure

Coordinates are evaluated against standard CSS pixels (96 dots per inch, where 1 millimetre corresponds to approximately 3.78 pixels).

Your result includes touchscreen contact area and hardware latency. All data remains strictly in volatile page memory and disappears on reload.