Free tool · Lighting Efficiency · Published 2026-10-14 · 500 words
LED Savings Calculator
Work Out Your Savings
Enter how many bulbs you are replacing, what they are, how long they are on each day and your electricity price. Add the price of the LEDs to see how fast they pay for themselves.
How It Works
Yearly saving = (old watts − LED watts) × hours per day × 365 ÷ 1,000 × your price per kWh × number of bulbs.
The default electricity price is 18.31 cents per kWh, the Energy Information Administration’s U.S. residential average for July 2026. Your own bill’s price per kWh, including delivery, will give a better answer.
Match the Lumens, Not the Watts
ENERGY STAR’s explanation: brightness is measured in lumens (not watts). The Department of Energy’s purchasing guide gives these equivalents:
| Old incandescent | Lumens to look for | Typical LED wattage |
|---|---|---|
| 40 W | 450 | 4.5 to 7 W |
| 60 W | 800 | 5.9 to 10.5 W |
| 75 W | 1,100 | 9.5 to 14 W |
| 100 W | 1,600 | 10.5 to 18 W |
Lighting is a smaller share of the bill than it used to be. EIA’s estimate for lighting is about 6% of home electricity use in 2020, so expect a modest saving unless your home still has many incandescent or halogen bulbs.
Lighting Is One Part of the Bill: Find the Rest
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Frequently Asked Questions
How much does switching to LED save per bulb?
It depends on the wattage difference, hours of use and your electricity price. For a 60-watt incandescent replaced by a 9-watt LED, on 3 hours a day at 18.31 cents per kWh, the calculator gives about $10 a year per bulb.
What LED replaces a 60-watt bulb?
One rated for about 800 lumens. The Department of Energy's purchasing guide puts that at 5.9 to 10.5 watts for an LED.
Is it worth replacing CFLs with LEDs?
The saving per bulb is small because CFLs are already efficient. Replace them as they fail, starting with the lights that are on longest.
Related Guides
- LED vs incandescent cost comparison — the full guide
- Energy-efficient lighting — the wider lighting plan
- Motion sensor switches — for lights that get left on
- Heat pump vs furnace calculator — our other free tool
