Question: how many lumens per square foot in bathroom?
Answer: To estimate the number of lumens your space will need, just multiply the square footage of your room by the number of foot-candles required for the space. For example, for a bathroom that is 64 square feet with a foot-candles range of 70-80, you'll need from 70x64 to 80x64 lumens, or 4480 – 5120 lumens.