Watts to Lumens Calculator

Find out how much light a bulb will produce based on its wattage and efficiency rating.

Φ_v(lm) = P(W) × η(lm/W)
9W LED bulb (90 lm/W) = 9 × 90 = 810 Lumens

How do I convert watts to lumens?

Multiply the electrical power in watts by the luminous efficacy (lumens per watt) of the bulb. Formula: Lumens = Watts × Luminous Efficacy.

How many lumens is a 60-watt bulb?

A traditional 60-watt incandescent bulb produces about 800 lumens. An LED bulb can produce the same 800 lumens using only 8 to 10 watts.

What is the efficacy of different light sources?

LEDs typically have an efficacy of 80-100 lm/W, fluorescents about 60 lm/W, and incandescent bulbs only 15 lm/W.