Fitts's Law & Hick's Law Simulator

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How it works

Fitts's Law predicts the time to move a pointer to a target from its distance D and width W:

MT = a + b · log2(D/W + 1)
ID = log2(D/W + 1)  — index of difficulty

Each round places a target at a random distance and size; your click-to-click time (MT) is measured and plotted against its ID. A least-squares fit over your own data gives real a, b coefficients — the fitted line's slope (b) is your effective "bits per second" throughput, and how tightly the points hug the line shows how well the law predicts real pointing behaviour.

Hick's Law predicts that decision time grows with the number of choices N:

RT = a + b · log2(N + 1)

Switch to the Hick's Law tab to click a named target inside menus that grow from 3 to 12 options — more choices should take measurably longer to decide between, even though the click itself is just as easy.

Fitts's Law pointing test

Click the cyan start dot, then click the yellow target as fast as you can. Distance and target size change every round — 10 rounds total.

Fitts's Law pointing test

Hick's Law choice test

Fitts's Law & Hick's Law Simulator