How many lumens do I need for each room?
A room-by-room table of target light levels, and how to turn them into a lumen figure you can shop with.
Watts tell you what a fixture consumes. Lumens tell you what it produces. Buy on lumens.
Target light levels by room
Corridors and stores are fine at 100 lux. Bedrooms sit around 150, living rooms 200, kitchens and classrooms 300, offices and retail 400, and inspection work 750.
The calculation
Area in square metres times target lux, plus 25 per cent. That is your total lumens.
Reading a specification honestly
Look for lumens per watt. Anything under 80 lm/W is old technology or an optimistic label. Also check CRI: below 80, colours look flat and food and fabric look wrong.
Frequently asked questions
How many lumens replace a 100W bulb?
About 1,400 lumens u2014 which is a 12u201314W LED at a realistic efficacy.