arayaroma/ether/ux-law-fitts-target

Fitts's Law / Minimize Target Distance

Time to reach a target is a function of distance to it and its size: T = a + b*log2(D/W + 1). Practically: bigger and closer targets are faster and more accurate to hit.

Rules of thumb

• Minimum touch target: 44x44px (iOS HIG) / 48x48dp (Material). Never ship a tappable icon smaller than that hit area, even if the visible glyph is smaller (pad the hit box).
• Primary action gets the largest, most reachable target on the screen — don't make "Cancel" and "Confirm" the same visual weight.
• Place related actions near the content they act on (row-level delete button next to the row, not in a far toolbar) to cut travel distance.
• Screen edges and corners are effectively infinite targets (cursor stops at the boundary) — good place for frequently used, hard-to-miss actions (OS menus exploit this).
• Avoid making users travel far and then hit a small target (e.g., a tiny "x" in a far corner of a large modal) — that's the worst combination under Fitts's Law.

Review checklist

1. Measure/estimate hit-box size on the smallest supported viewport.
2. Check spacing between adjacent tappable targets (avoid mis-taps) — 8px minimum gap.
3. Check distance from the triggering context to the resulting action.