Thanksgiving is November 26 this year, which means a lot of us will be on a ladder that Friday, untangling the same lights we’ve hung for a decade. Before you plug them in, it’s worth knowing what they cost to run. For most people using LEDs, the answer is pocket change. For anyone still hanging the big, warm, old-school incandescent bulbs along the roofline, the answer can be close to $100 for the season, and electricity isn’t getting cheaper.
The U.S. Energy Information Administration’s October Short-Term Energy Outlook puts the average 2026 residential electricity price at 18.2 cents per kilowatt-hour. That’s the number I used for every calculation below. Your own rate could be well above or below it, so grab your latest bill and look for the price per kWh before you trust any of my totals.
How to Figure Out What Your Lights Cost
The math is simple once you know a string’s wattage, which is printed on the tag near the plug or on the box. Multiply the watts by the hours the lights are on, divide by 1,000 to get kilowatt-hours, then multiply by your electricity rate.
For a typical season, I assumed the lights go up Thanksgiving weekend and stay on about 40 nights, six hours a night. That’s 240 hours total. Plenty of people run theirs longer (and some families leave them on until Valentine’s Day, which I respect), so adjust if that’s you.
The Numbers by Bulb Type
Start with the classic incandescent mini lights. Christmas Lights Etc. lists a 100-count incandescent mini string at 40 watts. Over 240 hours at 18.2 cents, that one string costs about $1.75. Their 70-count LED mini string draws roughly 4.8 watts, which works out to about 21 cents for the whole season.
Mini lights are cheap either way. The real money is in the big bulbs. According to Electric Choice, a 25-bulb incandescent C9 string pulls around 175 watts, and an incandescent C7 string about 125 watts. Run that C9 string for our 240 hours and you’re looking at roughly $7.64. A C7 string lands near $5.46. The LED versions of those same strings draw about 7 watts and 5 watts, costing around 31 cents and 22 cents.
So one string of old C9s costs about 25 times as much to run as its LED twin. That’s where a roofline adds up fast.
What a Normal House Display Costs
Picture a fairly ordinary setup: 10 strings of C9 bulbs tracing the roof and gutters, plus 15 strings of mini lights wrapped around bushes and the porch railing. Nothing that’ll get you on the local news.
With all incandescent bulbs, that display draws about 2,350 watts. Over the season it uses roughly 564 kWh and costs about $103. The same display in LEDs draws around 142 watts and costs about $6.20.
That’s a gap of nearly $97 a year, and it gets worse if you leave things on longer. Run that incandescent display 12 hours a night instead of six and the bill climbs past $200.
Then there are inflatables. Electric Choice estimates a 6-foot inflatable uses 100 to 200 watts because the fan runs the whole time it’s lit. At 150 watts and our 240 hours, one blow-up snowman costs about $6.55 for the season. That’s more than an entire roofline of LED C9s. I’m not saying evict the snowman. Just know he’s the most expensive thing in your yard if everything else is LED.
When Buying New LEDs Pays Off (and When It Doesn’t)
I’d push back a little on the usual “switch to LEDs!” advice. If you already own LED mini lights, you’re done. Buying new ones won’t save you anything meaningful, since the entire string costs about 21 cents a season to run.
If you’re still using incandescent minis, the savings per string is around $1.54 a year. That’s real, but slow. A new LED string has to last a few seasons before it pays for itself, so I’d replace those as they burn out rather than all at once.
The incandescent C7 and C9 bulbs are a different story. Swapping a C9 string saves about $7.33 a season at the national average rate, and more if your utility charges above 18.2 cents. Replace those first. ENERGY STAR says its certified LED light strings use 92% less energy than incandescent strands, can last up to 10 times longer, and come with a warranty of at least three years. If you’re buying anyway, look for that label so a dead string in year two isn’t your problem.
Timing matters too. The days after Christmas are usually when stores clear out holiday stock, so if your old strings are working fine this year, you can buy replacements on markdown in late December and swap them in next fall.
The Free Fix: Put Everything on a Timer
The single cheapest move is a plug-in outdoor timer. Most of us forget the lights are on and they run until we go to bed, or worse, all night. Cutting the incandescent display above from 12 hours a night to six saves about $100 over the season, and LED owners won’t notice much difference on the bill but will at least stop lighting up the neighborhood at 3 a.m.
Set the timer to switch on at dusk and off by 10 or 11 p.m. That covers the hours when people are actually driving by. If you’re on a time-of-use electricity plan, check when your peak window ends. Many evening peaks run right through the hours you’d want lights on, so a later start time could cut the cost further.
A few smaller habits help as well. Plug indoor tree lights into the same timer as a lamp, or just unplug them when you leave the room. Don’t daisy-chain more incandescent strings than the tag allows, both for safety and because those old strings tend to be the energy hogs anyway. And when you pack up in January, toss the strings with dead sections so you’re not tempted to hang half-working incandescents again next year.
Where to Put the Savings
A hundred dollars isn’t going to change anyone’s life, but December is the month where small leaks pile up fastest. If you make the switch or set a timer this year, consider moving the difference straight into a holiday sinking fund or a high-yield savings account the day your January electric bill comes in. Seeing that it came in lower than last year is satisfying. Seeing the money actually land somewhere is better.
Lights are supposed to be the fun part of the holidays. With LEDs and a timer, they can stay that way without showing up as a surprise on your January statement.
