Recessed Lighting Calculator

Plan recessed light spacing and quantity per room.

How It Works

  1. Enter room size. Type room area (sq ft), lumens per fixture, and target lumens/sq ft.
  2. Get fixture count. Fixtures = ⌈Area × Target ÷ Lumens⌉ — rounded up to whole lights.
  3. Set room dimensions. Enter length, width, and ceiling height for accurate spacing.
  4. Pick a room preset. Kitchen, bedroom, bathroom, etc. apply recommended lumens/sq ft.
  5. Plan the grid. See rows × columns, spacing, and wall clearance for even lighting.

Also try our Rafter Calculator or Construction Calculators.

Enter values to see results.

Formula & Reference

Fixtures = ⌈Area × Target / Lumens⌉