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LED vs Incandescent Christmas Lights: Energy, Cost and Safety

Updated November 1, 2026 · General information, not electrical or safety advice

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The short answer: LEDs win on running cost, life and heat. The Department of Energy says LED strands use 70 percent less energy, and puts the cost to light a 6-foot tree for 12 hours a day for 40 days at $0.27 with LEDs versus $10 with incandescents. ENERGY STAR says certified strings can last up to 10 times longer and stay cool to the touch.

Side by side

	LED	Incandescent
Energy use	DOE: LED strands use 70 percent less energy than conventional incandescent strands. ENERGY STAR: certified strings use about 92 percent less.	The baseline.
Cost to light a 6-foot tree, 12 hours a day for 40 days (DOE)	$0.27	$10
Lifespan	ENERGY STAR: certified LED strings can last up to 10 times longer. DOE: LEDs are sturdier and significantly less likely to burn out or break.	Bulbs burn out when the filament fails, which can break the circuit (DOE).
Heat	ENERGY STAR: cool to the touch, which lowers fire risk. Idaho Power: LEDs are safer because they produce less heat.	Hotter.
How many strands can you connect?	Follow the box. Mr. Electric says 265 feet of LED strands use about 38 watts, so one outlet can power a lot.	CPSC: never connect more than three sets. Mr. Electric says a comparable length uses 1,925 watts.
Warranty on certified strings	ENERGY STAR: at least three years.	Not covered by the ENERGY STAR sources we opened.

Sources: U.S. Department of Energy, ENERGY STAR, Idaho Power, CPSC, Mr. Electric (an electrical franchise).

DOE and ENERGY STAR give different percentages (70 versus 92). They measure different things: DOE is writing about LED strands in general, and ENERGY STAR about its certified strings. Either way, LEDs use far less power.

Our arithmetic

Using the DOE figures, one tree season costs about $9.73 less to run with LEDs ($10 minus $0.27). That is only the electricity for a 6-foot tree. A house with a lot of lights saves more, and LED strands usually cost more to buy. We found no source for typical LED strand prices, so we do not quote one.

What to look for

The ENERGY STAR label. ENERGY STAR says certified strings must use no more than 0.2 watts per bulb, carry a manufacturer warranty of at least three years, and, if labeled for outdoor use, pass weathering tests.
The right rating for where it goes. Use outdoor-rated strands outside (Bob Vila).
The fuse. DOE says the fuse is usually in the plug and is accessible through a small plastic door, and that it can be replaced. See last-minute lights for a quick fix.
The wattage. It is printed on the box. Use the calculator to check your outlet.

Mixing the two on one run is not covered by our sources. Follow the maker's instructions for each.

Need lights?

Pick outdoor-rated LED strings. Check the box for the wattage and for how many strands you can connect end to end.

Browse LED light strings Count what you need first

Common questions

Are LED Christmas lights worth it?

On running cost, yes. The Department of Energy says it costs $0.27 to light a 6-foot tree for 12 hours a day for 40 days with LEDs, and $10 with incandescents. ENERGY STAR says certified strings can last up to 10 times longer.

Do LED Christmas lights get hot?

ENERGY STAR says LED strings stay cool to the touch, which lowers fire risk. Idaho Power says LEDs produce less heat than incandescent bulbs.

How many LED strands can I connect together?

As many as the maker allows. The CPSC's three-set limit applies to incandescent lights. Check the box for the number and wattage.

Can I replace the fuse in a light string?

DOE says the fuse is usually in the plug, behind a small plastic door, and can be replaced. Check the box for the right fuse rating.

Related guides

Sources