Fitts's Law

Shrink Definition

Fitts's law describes how the time to reach a target depends on how far away it's and how big it is. Small, distant targets take longer to hit accurately than large, close ones. It's a remarkably reliable rule of movement, used everywhere from sports to designing buttons on a screen. It captures the built-in tradeoff between speed and precision in aiming.

Plain language

Reaching a small, far target takes longer than a big, near one.

Shrink Insight

The size and distance of a target set a hard limit on how fast you can hit it.

Why it matters

It gives a precise rule behind skilled movement and good design, from athletics to user interfaces. It grounds the speed-precision tradeoff in a testable law.

Common misunderstanding

People think practice can make any precise movement arbitrarily fast. There's a lawful limit set by target size and distance that training can't fully erase.

Shrink Perspective

Aiming has a math, and it favors big and near.

Shrink Reflection

Where could I make an important target bigger or closer?

Shrink Step

To move faster and more accurately, make key targets bigger or closer when you can.

Shrink Minute

Notice how much easier a large, near target is to hit than a small, far one.

Shrink Takeaway

Bigger and closer targets are faster to hit.

Medical boundary

Evidence summary

A highly reliable, mathematically precise law of motor behavior confirmed across decades and settings.