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

Lighting a 12 × 18 ft home office

Total light needed
9,720lumens
216 ft² × 45 foot-candles
Room area216ft²
Target light levelIES guidance for a home office45foot-candles
Total lumens9,720lm
Colour temperatureneutral white keeps alertness up4000K
Bulbs (800 lm each)13bulbs
Recessed cans (4 ft spacing)695 lm each14fixtures
Room
home office
Width
12 ft
Length
18 ft

Where 9,720 lumens comes from

Lighting is specified in foot-candles — lumens landing on each square foot of the surface you care about. A home office is worked to 45 foot-candles. Across 216 ft² that is 9,720 lumens in total.

Split it up

One fixture putting out 9,720 lumens and 14 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

4000K 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 9,720 lm fixture and 14 smaller ones add up the same but look completely different.

Nearby sizes