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Holiday lights electricity cost: LED vs incandescent
The math is the same as for any appliance. What changes the answer is the bulb: a single 7-watt incandescent bulb draws as much as 140 LEDs.
Price your lights at your own rateThe formula
Watts, hours, and your rate.
Holiday lights are priced like any other load: watts × hours ÷ 1,000 = kilowatt-hours, and kilowatt-hours × your rate = cost. The U.S. Energy Information Administration put the average residential price at 18.31¢ per kWh in July 2026; your bill gives your own. The wattage is printed on the package or the tag near the plug. See kilowatts versus kilowatt-hours if the units are unfamiliar.
Worked examples
6 hours a night for 40 nights, at 18.31¢ per kWh.
| Display | Watts | kWh for the season | Cost |
|---|---|---|---|
| One 100-bulb LED string at the ENERGY STAR ceiling of 0.2 W per bulb | 20 | 4.8 | $0.88 |
| Ten such LED strings | 200 | 48 | $8.79 |
| One 25-bulb string of 7-watt incandescent bulbs | 175 | 42 | $7.69 |
| Ten such incandescent strings | 1,750 | 420 | $76.90 |
The LED rows use the most a certified string may draw per bulb; many draw less, so check the label. The 240 hours assume lights on from dusk to late evening for about six weeks; a timer keeps them to that.
Why LEDs change the answer
About 92% less energy, per ENERGY STAR.
ENERGY STAR says certified decorative light strings use about 92% less energy than conventional incandescent strings, may draw no more than 0.2 watts per bulb, and carry a warranty of at least three years. Its comparison: the electricity used by one 7-watt incandescent bulb could power 140 LEDs, enough for two 24-foot strings. Certified LED strings can last up to 10 times longer, have no filaments or glass, and stay cool to the touch, which reduces fire risk. Many offer dimming and color shifting, and strings labeled for outdoor use have passed weathering tests.
Your own number
Add up the strings, then the hours.
- Read the watts on each string, inflatable, and projector, and add them. If a tag lists only amps, amps × 120 gives approximate watts.
- Decide the hours per night and the number of nights.
- Use your bill’s price per kWh, including delivery charges.
Inflatables with blowers and older incandescent displays are where the large numbers come from. The appliance energy cost calculator can hold each item as a separate line, so you can see which one matters.
Check them before they go up
Electrical problems start many tree fires.
The U.S. Fire Administration, citing NFPA, says almost one-third of home Christmas tree fires are caused by electrical problems. Its checklist: inspect lights every year before putting them up and throw away strings with frayed or pinched wires; follow the manufacturer’s instructions on how many strings to connect; water a live tree every day, because a dry tree burns very hot and very fast; keep the tree at least 3 feet from fireplaces, radiators, space heaters, candles, and heat vents; and keep candles at least 12 inches from anything that can burn.
3 SOURCESSource ledger
Check the basis.
QUESTIONS THIS ANSWERS
Questions this answers
How much does it cost to run Christmas lights?
Multiply the watts by the hours, divide by 1,000 for kilowatt-hours, and multiply by your rate. A 25-bulb string of 7-watt incandescent bulbs, 175 watts, run 6 hours a night for 40 nights uses 42 kWh, about $7.69 at the U.S. average of 18.31 cents per kWh.
How much do LED holiday lights save?
ENERGY STAR says certified decorative light strings use about 92% less energy than conventional incandescent strings, are limited to 0.2 watts per bulb, and can last up to 10 times longer.
Where do I find the wattage of a light string?
On the package or on the tag near the plug. If only amps are listed, multiply amps by 120 volts for an approximate wattage.