## Watts to lumens calculation/conversion

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)}