What this calculator does
Holiday lights, inflatables and lit yard figures run for hours every night for weeks. This calculator adds up your display, multiplies it by the hours a night and the nights of the season, and prices the electricity at the latest average home electricity price in your state from the U.S. Energy Information Administration (EIA). A second card compares the same number of light strings as LED and as incandescent.
How the numbers work
- Watts of a line = how many × watts each.
- kWh for the season = all the watts × hours a night × nights ÷ 1,000.
- Cost = kWh × your price per kWh.
- LED savings = the same calculation for incandescent strings minus the one for LED strings.
The watts are on the box, the tag on the cord or the product page. The defaults in the calculator are only examples.
An example
Ten LED strings of 5 watts, two incandescent strings of 40 watts and one 150-watt inflatable use 280 watts together. Six hours a night for 40 nights is 67.2 kWh. At an example price of 17.5 cents per kWh, that is about $11.76 for the season. Ten LED strings of 5 watts would cost about $2.10 over the same season, and ten incandescent strings of 40 watts about $16.80.
Tips
- Use a timer, so the lights are on only in the evening hours you want.
- Check cords and plugs for damage, and use lights rated for outdoor use outside.
- Add the total to your holiday budget, and see your whole bill with the electricity bill calculator.
Frequently asked questions
How much do Christmas lights add to the electric bill?
It depends on the watts, the hours and your price per kWh. A display of a few hundred watts on for six hours a night over the season usually adds dollars, not hundreds of dollars, at typical prices; large incandescent displays cost much more.
Do LED lights really use less electricity?
Yes, usually far less. Compare the watts printed on the boxes: an LED string with the same number of bulbs often uses a small fraction of the watts of an incandescent one.
Which electricity price does the calculator use?
The latest monthly average residential price for your state published by the EIA, or your own price if you type it. Your bill shows your real price per kWh.
Is my list saved?
No. The numbers stay in your browser and are not sent to us.