Lighting a 18 × 18 ft home office
Total light needed
14,580lumens
324 ft² × 45 foot-candles
| Room area | 324ft² |
|---|---|
| Target light levelIES guidance for a home office | 45foot-candles |
| Total lumens | 14,580lm |
| Colour temperatureneutral white keeps alertness up | 4000K |
| Bulbs (800 lm each) | 19bulbs |
| Recessed cans (4 ft spacing)695 lm each | 21fixtures |
- Room
- home office
- Width
- 18 ft
- Length
- 18 ft
Where 14,580 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 324 ft² that is 14,580 lumens in total.
Split it up
One fixture putting out 14,580 lumens and 21 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 14,580 lm fixture and 21 smaller ones add up the same but look completely different.