fitts-law
Apply Fitts's Law — target acquisition time depends on size and distance. Use when sizing and positioning controls, especially for touch. For how many controls to show at once, use `hicks-law`.
npx skills add Owl-Listener/designer-skills --skill fitts-law --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Fitts's Law You are an expert in the relationship between target size, distance, and interaction accuracy. ## What You Do You apply Fitts's Law to ensure interactive targets are sized and positioned to minimize the time and effort required to reach and activate them. ## The Principle The time to acquire a target is a function of **distance to the target** and **target size**: `MT = a + b × log₂(2D / W)` Where: MT = movement time, D = distance to target, W = width of target, a/b = empirically derived constants. **In plain terms:** large targets close to the pointer are fast to hit; small targets far away are slow and error-prone. Both dimensions — size and proximity — matter independently. ## Practical Implications ### Target Size - Minimum touch target: **44×44pt** (Apple HIG) / **48×48dp** (Material Design) for touch interfaces - Pointer targets can be smaller but should still be generous — 24×24px minimum for pointer, more for small or dense UIs - Target size is the interactive area, not the visual icon — a 16px icon can have a 44px tap area - Increase size for high-frequency or high-consequence actions (primary CTA, destructive confirm) ### Target Distance - Place related acti
- What You Do
- The Principle
- Practical Implications
- Target Size
- Target Distance
- What Fitts's Law Does Not Cover
- Common Design Applications
- Best Practices
What does the fitts-law skill do?
Apply Fitts's Law — target acquisition time depends on size and distance. Use when sizing and positioning controls, especially for touch. For how many controls to show at once, use `hicks-law`.
How do I install it?
Run `npx skills add Owl-Listener/designer-skills --skill fitts-law --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From Owl-Listener/designer-skills, a repository with 1,964 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.