Estimate savings from replacing an always-on light with a motion sensor.
A motion sensor cuts the same wattage's runtime from many hours to a few minutes a day. Comparing the yearly costs before and after gives the payback on the sensor. Outdoor and closet lights left on are a constant drain, so a cheap sensor investment recovers quickly through reduced electricity.
Motion Sensor Payback
Payback = sensor cost / annual savings
Payback = sensor cost / annual savings A motion sensor cuts the same wattage's runtime from many hours to a few minutes a day. Comparing the yearly costs before and after gives the payback on the sensor.
Outdoor and closet lights left on are a constant drain, so a cheap sensor investment recovers quickly through reduced electricity.
This calculator takes 5 inputs: Light wattage, On time with sensor, On time without sensor, Electricity rate, Sensor cost. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.