Lumens to Watts Calculator

Find the wattage for a target brightness.

Power (W) 10

Formula: watts = lumens ÷ efficacy

Step-by-step with your numbers:

1. Values used:

2. Brightness = 800 lm

3. Efficacy = 80 lm/W

5. Power = Brightness / Efficacy = 800 / 80 = 10W

Did we solve your problem today?

Convert light output (lumens) to power (watts) using luminous efficacy.

The math behind it

watts = lumens ÷ efficacy. LEDs ≈ 80–100 lm/W; incandescent ≈ 15 lm/W.

800 lm at 80 lm/W → 10 W (LED).

Why LEDs save?

Higher efficacy means the same brightness for far fewer watts.