# Watts to lumens calculator

Electric power in watts (W) to luminous flux in lumens (lm) calculator and how to calculate.

Enter the power in watts,
luminous efficacy in lumens per watt and press the *Calculate* button to get the luminous flux in lumens:

* the predefined luminous efficacy values are typical / average values.

## Watts to lumens calculation

Energy saving lamps have high luminous efficacy (more lumens per watt).

The luminous flux *Φ*_{V} in lumens (lm) is equal to the power P in watts (W), times the luminous efficacy * η* in lumens per watt (lm/W):

*Φ*_{V(lm)} = *P*_{(W)} × *η*_{(lm/W)}