How much does it cost to run string lights?
We've pre-filled typical string lights below. Set your electricity rate and adjust the hours to match how you use yours — the cost updates instantly.
String lights are one of the cheapest things you'll ever plug in, and the reason is simple: even a whole strand is usually pulling less wattage than a single light bulb. A typical set draws around 30 watts, and LED strands can run as low as 5 watts — so leaving them on for hours barely registers next to appliances that pull hundreds or thousands of watts.
The real cost swing isn't the outlet, it's the bulb technology. Older incandescent mini-lights and decorative sets can pull several times more power than an equivalent LED strand for the same amount of sparkle, and if you're running multiple strands end-to-end around a porch, tree, or room, that difference compounds fast. Left on all evening through a season, the gap between LED and incandescent is usually the only thing that turns 'basically free' into a noticeable line item.
What drives the cost of running string lights
- Bulb type: LED strands sip a few watts total, while incandescent or decorative sets can pull 5-10x more for the same length
- How many strands you daisy-chain together — cost scales directly with total combined wattage, not per-strand price
- Hours per day they're lit, especially if left on overnight or all season rather than just evenings
How to cut it
- Switch incandescent or decorative strands to LED — same look, a fraction of the draw
- Put them on a timer or smart plug so they're not accidentally running all day or overnight
- Combine fewer, longer LED runs instead of overlapping multiple strands in the same space
- Reserve incandescent/novelty sets for short display windows (evening hours only) rather than all-day use
Common questions
How much does it cost to run string lights per month?
At a typical 30W and about 5 hours a day, string lights costs roughly $0.77 a month at $0.17/kWh. Set your own rate and hours above for an exact figure.
How can I cut the cost of running string lights?
Switch incandescent or decorative strands to LED — same look, a fraction of the draw
Are LED string lights really that much cheaper than incandescent ones?
Yes. For the same length and brightness, incandescent mini-lights typically use several times more wattage than LED strands, so swapping is usually the single biggest cost lever for this category — bigger than changing how many hours you run them.
Does it cost more to run string lights all season instead of just a few hours a night?
It scales linearly with hours, so leaving lights on 12 hours a day instead of 5-6 roughly doubles the cost — but because the wattage is so low to begin with, even 'all season, all night' usually stays under a few dollars total for a typical LED display.
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