Lumens to Watts Calculator

Convert Lumens (Brightness) to Watts (Power) for LED, CFL, Halogen, and Incandescent bulbs.

800 lm ≈ Standard 60W bulb

Lumens vs. Watts: What's the Difference?

For decades, we bought light bulbs based on Watts, which measures energy consumption. However, with the advent of energy-efficient lighting like LEDs, Watts are no longer a good indicator of brightness.

Instead, we should look at Lumens (lm), which is the direct measure of visible light output.

Luminous Efficacy

Different technologies produce light with varying degrees of efficiency. This is known as "Luminous Efficacy" (Lumens per Watt).

Bulb Type Efficiency (lm/W) Lifespan
Incandescent 10 - 17 lm/W 1,000 hours
Halogen 16 - 24 lm/W 2,500 hours
CFL 45 - 75 lm/W 10,000 hours
LED 80 - 120+ lm/W 25,000+ hours

Common Brightness Standards

Use this quick reference to find the right replacement bulb:

  • 450 Lumens: Replaces a 40W Incandescent. Good for bedside lamps.
  • 800 Lumens: Replaces a 60W Incandescent. Standard for living rooms and bedrooms.
  • 1100 Lumens: Replaces a 75W Incandescent. Good for kitchens and workspaces.
  • 1600 Lumens: Replaces a 100W Incandescent. Very bright, for large rooms or garages.

Calculation Formula

To estimate the wattage required for a specific brightness:

Watts = Lumens / (Lumens per Watt)

Example: To get 800 lumens from an LED (approx. 100 lm/W): 800 / 100 = 8 Watts.