Calculate LED power consumption, efficacy and the running cost of a lighting installation.
Efficacy is the figure that matters when comparing fittings: modern LEDs reach 100 to 150 lm/W against about 15 lm/W for incandescent. Running cost follows directly from total power and hours. Lighting often runs 10 hours a day or more, so efficacy differences compound into large annual savings even at modest installed power.
LED Power
Efficacy = lumens ÷ watts; annual energy = total watts × hours × 365 ÷ 1,000
Efficacy = lumens ÷ watts; annual energy = total watts × hours × 365 ÷ 1,000 Efficacy is the figure that matters when comparing fittings: modern LEDs reach 100 to 150 lm/W against about 15 lm/W for incandescent. Running cost follows directly from total power and hours.
Lighting often runs 10 hours a day or more, so efficacy differences compound into large annual savings even at modest installed power.
This calculator takes 5 inputs: Number of LEDs or fittings, Power per fitting, Light output per fitting, Hours per day, Energy price per kWh. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.