Marketing, sales & UX laws · law 040
Fitts's Law
By Shivam Bhandari · Reviewed 31 October 2026 · How we write
what it means
The time to reach a target depends on its distance and size — big, close targets are fastest to hit.
How Fitts's Law works
On screens, Fitts's law means important buttons should be large and placed where the thumb or cursor already is. Small, distant buttons are slower to hit and easier to miss.
It also explains why mobile designs put primary actions at the bottom of the screen within easy thumb reach.
where it comes from
Psychologist Paul Fitts published it in 1954 after studying how quickly people could move to and tap targets.
Fitts's Law examples in business
Mobile checkout
Making the ‘Pay now’ button full-width at the bottom of the screen reduces missed taps.
Retail
Impulse items are placed right at the billing counter — the shortest possible ‘reach’.
Forms
Tiny checkboxes are replaced by full-row tap areas on mobile.
How to apply it
- 1Make your main call-to-action the largest clickable element.
- 2Place it close to where attention and the thumb already are.
- 3Keep destructive actions (delete, cancel) smaller and farther away.
- 4Test key flows on a real phone with one hand.
common misreading
Bigger is not always better — oversized elements can crowd the page. The goal is easy reach for the right actions.
ask yourself
Is your most important button the easiest thing on the page to tap?
Frequently asked questions
What is Fitts's Law?
The time to reach a target depends on its distance and size — big, close targets are fastest to hit. On screens, Fitts's law means important buttons should be large and placed where the thumb or cursor already is. Small, distant buttons are slower to hit and easier to miss.
Who came up with Fitts's Law?
Psychologist Paul Fitts published it in 1954 after studying how quickly people could move to and tap targets.
How do you apply Fitts's Law in business?
1. Make your main call-to-action the largest clickable element. 2. Place it close to where attention and the thumb already are. 3. Keep destructive actions (delete, cancel) smaller and farther away. 4. Test key flows on a real phone with one hand.
What is a common misunderstanding of Fitts's Law?
Bigger is not always better — oversized elements can crowd the page. The goal is easy reach for the right actions.