Fitts’s Law: Why Every UX Practitioner Should Know It
A FuguUX blog post (by Ziyan Tan, July 18 2025) introducing Fitts’s Law — that the time to reach a target is proportional to its distance and inversely proportional to its size — as a rationale UX practitioners can point to instead of relying on intuition alone, across mouse, trackpad, and touch input alike.
License: FuguUX’s own published content — proprietary, not externally licensed
Key points
- Increase button/icon size: larger interactive elements reduce click errors and speed up interaction; test different sizes against real users to find where the miss-rate actually drops off, rather than assuming a size is big enough.
- Keep critical actions close, not below the fold and far away: positioning a high-value action (e.g. a payment button) near where a customer already is reduces the physical distance they have to travel to complete the task.
- Label an icon, don’t leave it bare: adding a text label next to an icon enlarges the icon’s overall clickable target area, beyond just adding clarity about what it does.
- Testing with real users remains essential: a designer’s own sense of what’s “big enough” or “close enough” doesn’t reliably match how users actually experience a target.