Thumb Reach Heatmap Matrix
Physical limits of standard hand sizes on 6.5"+ screens.
As average smartphone screens stretch beyond 6.5" diagonally with 20:9 aspect ratios, the "Thumb Zone" (first proposed by Steven Hoober) has physically collapsed.
Over 60% of the screen area is now inaccessible to a single-handed bottom grip without shifting the device or risking a drop.
Ergonomic Action Placements
- Top 20%: Destructive/Rare actions (Settings, Logout)
- Middle 40%: Read-only content, scroll origin
- Bottom 40%: Core navigation, Primary CTAs