Free tool · The Design Lab
The Room Lighting Calculator
Enter your dimensions, ceiling height, and natural light. Get lumen targets for ambient, task, and accent, plus the fixture count and spacing to hit them. The framework comes from Guide 01. The calculator is free, and you can run it as many times as you need.
The problem
How many can lights does this room need?
It is a hard question to answer in the aisle. The number on the box was written for a warehouse, and a round figure from the floor associate is a guess dressed up as an answer. Rooms end up over-lit and flat, or dark in the corners, because no one ran the room's real size against the light it needs.
How the calculator fixes it
The room decides the number.
The calculator takes your dimensions, ceiling height, and daylight, then works back to the light the room needs.
- Lumen targets for ambient, task, and accent.
- Recessed fixture count and spacing.
- Color temperature for the room.
Length ft
in
Width ft
in
Ceiling ft
in
Room dimensions must be at least 2 feet.
4" casts a tighter beam. Same brightness target, more fixtures, cleaner ceiling.
Enter your room details
to see the plan.
Your Lighting Plan
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Next Step
These are your targets. The Residential Lighting Reference Guide covers the exact mounting heights, spacing formulas, and specifications behind every number above.
See Guide 01 · $37The calculator handles the math.
Guide 01 covers the rest. Fixture types, color temperature, three-layer composition, and the room-by-room application specs the calculator doesn't have space for.
See Guide 01