LED bulb savings calculator
Compare the old bulb wattage with an LED of the same brightness to see the real saving.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter old bulb power, led bulb power, number of bulbs, hours per day, price per kwh and price per led bulb.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Yearly kWh saved = (old W minus LED W) × count × hours × 365 ÷ 1000. Payback months = bulb cost ÷ monthly saving.
Example
Inputs: Old bulb power = 60 W, LED bulb power = 9 W, Number of bulbs = 10, Hours per day = 6, Price per kWh = 0.18 per kWh. Result: Yearly saving: 201.04; Energy saved per year: 1,116.9 kWh; Monthly saving: 16.75.
Limits and caveats
- Compare bulbs of the same brightness in lumens; a 9 W LED roughly replaces a 60 W incandescent.
- It ignores the longer LED life and the cost of repeated replacements.
Questions about this tool
How much does an LED bulb save?
Swapping 60 W for 9 W saves 51 W, about 85% of the lighting energy for that bulb.
When do the bulbs pay for themselves?
In the example, 10 bulbs at 10 each pay back in about 6 months at 6 hours a day.
Does the saving include air conditioning?
No. LEDs give off less heat and ease the AC load a little in summer, which is not counted here.