Lumens to watts (W) conversion calculator
Lumens to watts calculation formula. Energy saving lamps have high luminous efficacy (more lumens per watt). The power P in watts (W) is equal to the luminous flux ΦV in lumens (lm), divided by the luminous efficacy η in lumens per watt (lm/W): P(W) = ΦV(lm) / η(lm/W)