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How Much Do Christmas Lights Cost to Run?
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The sourced numbers
| Fact | Figure | Source |
|---|---|---|
| Cost to light a 6-foot tree, 12 hours a day for 40 days | $0.27 with LEDs, $10 with incandescents | U.S. Department of Energy (article dated Dec. 16, 2015) |
| Energy use of LED strands | 70 percent less than conventional incandescent strands | U.S. Department of Energy |
| Energy use of ENERGY STAR certified strings | About 92 percent less than conventional incandescent strings | ENERGY STAR |
| Efficiency limit for certified strings | No more than 0.2 watts per bulb | ENERGY STAR |
| Comparison | One 7-watt incandescent bulb uses the electricity that could power 140 LEDs | ENERGY STAR |
| Heat | LEDs are more efficient and safer because they produce less heat | Idaho Power |
The DOE page does not say what electricity rate sits behind its dollar figures, and it is from 2015. Treat it as a size comparison, not a quote for your bill.
How to work out your own cost
This is our arithmetic. The formula is standard unit conversion, not a quoted rule.
Cost = watts ÷ 1,000 × hours × your price per kWh.
- Watts: printed on the box or tag. Add up every strand.
- Hours: hours per night times the number of nights.
- Price per kWh: on your electric bill. We do not quote a national price because it varies by utility.
Worked example (the rate is made up to show the math)
Take one 100-bulb LED strand. If it just meets ENERGY STAR's limit of 0.2 watts per bulb, it uses at most 20 watts (100 × 0.2). Run it 12 hours a day for 40 days: 480 hours. That is 20 ÷ 1,000 × 480 = 9.6 kWh.
| Your rate per kWh | Cost for 9.6 kWh |
|---|---|
| $0.10 | $0.96 |
| $0.15 | $1.44 |
| $0.20 | $1.92 |
Example rates only. Use the price on your bill. A real strand may use fewer watts than the limit, so read the box.
Doubling the hours doubles the cost, and halving them halves it. A timer that shuts the lights off at bedtime is the easiest saving. See timers and extension cords.
Watch the other loads
- Inflatables and motors are not light strands. Check the watts on the label. See inflatables.
- Old incandescent strands use more watts per bulb. Read the tag, not the age.
Want the whole comparison, with lifespan and strand limits? See LED vs incandescent. To check how many watts one outlet can take, use the calculator.
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 stringsCount what you need firstCommon questions
How much does it cost to run Christmas lights?
The Department of Energy puts it at $0.27 to light a 6-foot tree for 12 hours a day for 40 days with LEDs, versus $10 with incandescents. Your cost depends on the watts, the hours and your electric rate.
How do I calculate what my lights cost?
Multiply the total watts by the hours they run, divide by 1,000 to get kilowatt-hours, then multiply by the price per kWh on your bill. This is basic arithmetic, not a quoted rule.
Do LED Christmas lights really use less power?
Yes. The Department of Energy says LED strands use 70 percent less energy than conventional incandescent strands. ENERGY STAR says certified strings use about 92 percent less.