Lumens Calculator
How many lumens you need to light a room.
Floor area: 180 sq ft
Target light level: 30 foot-candles
Total lumens: 5,400
Approx LED wattage: 63 W (LED, ~9 W per 800 lm)
Bulb lumen quick reference
- 40 W incandescent ≈ 450 lm
- 60 W incandescent ≈ 800 lm
- 75 W incandescent ≈ 1100 lm
- 100 W incandescent ≈ 1600 lm
Foot-candle targets follow IESNA Lighting Handbook recommendations. Layer your light: ambient first, then task, then accent. Add dimmers if you can. Older eyes need more light.
About
Pick the room type and enter dimensions. The tool multiplies floor area by the IESNA recommended foot-candles for that room and returns total lumens, plus how many bulbs you need at a given lumen output.
How to use
- Enter the room dimensions.
- Pick the room type.
- Enter your bulb's lumens.
FAQ
Watts or lumens?+
Lumens. Watts measure power draw, lumens measure light output. A modern 9 W LED puts out the same 800 lm as a 60 W incandescent.
Are these foot-candle targets right for me?+
They follow the IESNA Lighting Handbook. Bump up by 30 to 50 percent if you're over 60 or work on detailed crafts.