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

How many lumens for a 20 × 20 ft bathroom?

Total light needed
14,000lumens
400 ft² × 35 foot-candles
bathroom · 20×20 ft20 ft20 ft14,000 lumens total · about 18 fixtures · 3000–4000K
Room area400ft²
Target light levelIES guidance for a bathroom35foot-candles
Total lumens14,000lm
Colour temperatureadd vanity lights at face height3000–4000K
Bulbs (800 lm each)18bulbs
Recessed cans (4 ft spacing)560 lm each25fixtures

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 14,000 lm fixture and 25 smaller ones add up the same but look completely different.

Where 14,000 lumens comes from

Lighting is specified in foot-candles — lumens landing on each square foot of the surface you care about. A bathroom is worked to 35 foot-candles. Across 400 ft² that is 14,000 lumens in total.

Split it up

One fixture putting out 14,000 lumens and 25 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.

Color temperature

3000–4000K suits this room. Warmer light reads as relaxed and is what you want where people wind down; cooler light keeps edges and colors crisp, which matters where there is work to do.

Nearby sizes

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