KelvinPlanHow much light each room needs, and what colour it should be.

Lighting a 18 × 20 ft garage

Total light needed
18,000lumens
360 ft² × 50 foot-candles
Room area360ft²
Target light levelIES guidance for a garage50foot-candles
Total lumens18,000lm
Colour temperaturecool white for detail work4000–5000K
Bulbs (800 lm each)23bulbs
Recessed cans (4 ft spacing)783 lm each23fixtures
Room
garage
Width
18 ft
Length
20 ft

Where 18,000 lumens comes from

Lighting is specified in foot-candles — lumens landing on each square foot of the surface you care about. A garage is worked to 50 foot-candles. Across 360 ft² that is 18,000 lumens in total.

Split it up

One fixture putting out 18,000 lumens and 23 fixtures adding up to the same number light a room very differently. A single source throws hard shadows and glare; several spread the light and make the room feel larger. Aim for layers — ambient, task, and something low for the evening.

Colour temperature

4000–5000K suits this room. Warmer light reads as relaxed and is what you want where people wind down; cooler light keeps edges and colours crisp, which matters where there is work to do.

Notes

  • Foot-candles are lumens per square foot at the work surface. Ceilings above 9 ft, dark walls or dark flooring all eat light — add roughly 10% per extra foot of ceiling height.
  • Spread the total across several fixtures rather than one bright source. One 18,000 lm fixture and 23 smaller ones add up the same but look completely different.

Nearby sizes