Lumens to Watts Converter

LED, CFL, halogen or old-school incandescent: pick the light source, enter the lumens you need, and we estimate how many watts the lamp will draw. You can also go backwards (watts → lumens).

1. Lumens → Watts

≈ common 60W incandescent light

watts = lumens ÷ lm/W

2. Watts → Lumens

e.g. LED 10W bulb

We reuse the lm/W chosen above.

lumens = watts × lm/W

Current efficacy: 100 lm/W

Real fixtures have drivers, optics and dirt over time, so treat this as a practical estimate.

Common lighting equivalents

Old incandescent Approx. lumens LED (100 lm/W) Notes
40 W450 lm4.5 WSmall room, hallway
60 W800 lm8 WMost common bulb
75 W1100 lm11 WBrighter task light
100 W1600 lm16 WLarge room

Why lumens and watts aren’t the same thing

Watt (W) is electrical power. Lumen (lm) is visible light output. Two lamps with the same wattage can produce very different lumen levels depending on their efficiency (lm/W).

Formulas

watts = lumens ÷ (lumens per watt)

lumens = watts × (lumens per watt)

Example: 1,200 lm with LED 100 lm/W:

watts = 1200 ÷ 100 = 12 W

Typical efficacies (rule of thumb)

  • Incandescent: 10–15 lm/W
  • Halogen: 15–20 lm/W
  • CFL: 60–75 lm/W
  • LED household: 80–110 lm/W
  • Good LED panel/strip: 110–130 lm/W

FAQ

1. How many watts is 800 lumens?

At 100 lm/W (typical LED), 800 ÷ 100 = 8 W.

2. How many lumens is a 10W LED?

10 × 100 = 1,000 lm if it’s a decent LED. Use your real fixture’s lm/W for a better number.

3. Can I use this for outdoor lighting?

Yes — pick the LED value closest to your product datasheet, or enter custom lm/W.