Tool · Investor Sam Green

LED vs Incandescent Bulb Savings Calculator

June 30, 2026 • By the Investor Sam Editorial Team • Reviewed by Berly Sam Varghese, Editor
LED bulbs use roughly a fifth to a tenth of the electricity of an old incandescent to produce the same light, and they last far longer. This calculator adds up how many kilowatt-hours and dollars you save each year by switching, based on the number of bulbs, their old and new wattages, how many hours they run, and your electricity rate.

Example: Number of bulbs: 20 bulbs · Old bulb wattage: 60 W · LED wattage: 9 W · Hours on per day: 4 hrs · Electricity rate: 0.17 $/kWh

Annual savings$253
Electricity saved per year1,489.2
Old bulbs' yearly cost$298

Worked example

Swap 20 bulbs from 60-watt incandescents to 9-watt LEDs, each running 4 hours a day. The old bulbs drew 60 watts, the LEDs draw 9, saving 51 watts per bulb. Across 20 bulbs and 1,460 hours a year that is about 1,489 kWh saved, worth roughly $253 a year at $0.17 per kWh. The bulbs cost a few dollars each and last for years, so the payback is measured in months.

Frequently asked questions

How much less power does an LED use?

An LED typically uses 75 to 85% less energy than an incandescent of the same brightness. A 60-watt incandescent is matched by roughly a 9-watt LED. That gap, multiplied across every bulb and every hour they run, is where the savings in this calculator come from.

Do LEDs really last longer?

Yes, dramatically. LEDs are commonly rated for 15,000 to 25,000 hours or more, versus about 1,000 hours for an incandescent. Beyond the electricity savings shown here, you replace bulbs far less often, which adds convenience and reduces waste this tool does not even count.

Which bulbs are worth switching first?

Start with the bulbs that run the most hours per day — kitchens, living rooms, porch and security lights — because savings scale directly with run time. A rarely used closet bulb saves little, while a porch light left on all night pays back almost immediately.

Are LEDs worth it if I already have some?

Only the incandescent or halogen bulbs you still have left to replace generate new savings; bulbs already switched to LED are done. Enter just the remaining old bulbs to see the savings still on the table.

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Sources

Berly Sam Varghese · Editor, Investor Sam

Berly Sam Varghese is an engineer who treats money the way he treats any hard problem — something to be engineered, not gambled on. He funded years of education and built real financial stability the patient way, by living below his means and investing rather than borrowing. He writes for the person trying to make a greener choice that also makes financial sense. He reviews and approves every article on Investor Sam and checks the figures against primary sources before anything is published. More about our standards.