What wattage should I enter for the LED replacement?

A typical LED equivalent uses about 8–10 W to replace a 60 W incandescent, or 13–15 W to replace a 100 W bulb. Check the box of your LED bulb for the exact wattage.

What electricity rate should I use?

The US average is roughly $0.13–$0.16 per kWh. Check your utility bill for your exact rate. The calculator defaults to $0.13/kWh.

Does the payback period include the cost of the old bulb?

No — it covers only the upfront cost of the LED bulb itself, since you are replacing a bulb that has already burned out or that you are proactively swapping. If you want to factor in the old bulb cost, subtract it from the LED price field.

How accurate are the savings figures?

The calculation assumes constant daily usage at the hours you enter. Real savings vary with seasonal use patterns, dimmer switches, and bulb lifespan differences.

Do LEDs save money even in rooms used only briefly?

Yes, though the payback period is longer. Even a closet light on 15 minutes per day will save energy over years of use.

LED Savings Calculator

Calculate annual energy cost savings and payback period when switching from incandescent or halogen bulbs to LED.

Bulb Details

Current bulb wattage (W)

Typical: 40 W, 60 W, 75 W, or 100 W incandescent

LED replacement wattage (W)

Typical: 8–10 W replaces 60 W, 13–15 W replaces 100 W

Number of bulbs

Daily usage per bulb (hours)

Electricity rate ($/kWh)

US average ~$0.13. Check your utility bill.

LED bulb price ($/bulb) (optional)

Used to calculate payback period. Set to 0 to skip.

Annual Savings

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kWh saved / year

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$ saved / year

Annual Running Cost

Current bulbs

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LED bulbs

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Payback Period

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5-Year Cumulative Savings

Year	Savings	Net (after LED cost)
Enter values to see projection

Summary

This calculator compares the running cost of traditional incandescent or halogen bulbs against modern LED equivalents. Enter the wattage of both bulb types, how many hours per day they run, the number of bulbs, and your electricity rate to see your annual savings and how quickly the LED investment pays for itself.

How it works

Enter the wattage of your current incandescent or halogen bulb.
Enter the wattage of the LED replacement bulb.
Set the number of bulbs, daily usage hours, and your electricity cost per kWh.
Optionally enter the LED bulb purchase price to calculate the payback period.
The calculator instantly shows annual energy saved, money saved per year, and months to break even.

Use cases

Estimate savings before buying LED bulbs for a whole house.
Justify LED upgrades in rental properties or commercial spaces.
Compare different LED options to find the best value.
Calculate how long before LED bulbs pay for themselves.
Present energy-saving ROI to a landlord or facilities manager.
Plan a phased lighting upgrade across multiple rooms.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu