Design & Accessibility
What is Fitts's Law?
Fitts's Law states that the time to click a target grows with distance and shrinks with size — large targets close to the cursor are faster.
The law explains why large centered CTAs convert more than small corner ones, and why screen corners (infinitely-large targets — you can't overshoot) are prime real estate (Apple puts menu there).
On mobile, the rule becomes "touch targets ≥ 44×44px" (Apple HIG) or 48×48px (Material). Buttons smaller than that are mistapped in 30%+ of cases.
Frequently asked questions
Is a 44px button universal?
It is the minimum recommended by Apple HIG. Material Design uses 48px. Below that, touch error rate climbs sharply.
Does it apply on desktop too?
Yes, but with less rigor (mouse is more precise than finger). Targets that are too small still slow users and tire them.