Power, Cords & Timers
How many watts and amps do Christmas lights use?
The number is printed on the set. Everything else is one division, and it is the division that prevents a tripped breaker.
Mike M. — The hands-on owner behind Iron Mako Media.
Published
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Short answer: the wattage is printed on a small tag near the plug on every light set. Add up the wattage of everything you are running, divide by 120, and you have amps. Compare that with 12 amps, which is the working budget on a standard 15-amp circuit.
We are deliberately not publishing a table of typical wattages here. Draw varies enormously with bulb type, bulb count, LED efficiency and whether the set has a controller, and a made-up average would be worse than useless when your actual figure is printed on the product in your hand.
Where to find the number
- The plug tag. A small plastic tag on the cord near the plug carries the wattage and the maximum end-to-end connection count. This is the authoritative figure.
- The box. If you still have it, the specification panel states it.
- The manufacturer's listing. Search the exact product name — the specification is almost always published.
- The controller, on sets that have one. Some state the figure there rather than on the plug.
The arithmetic
Two formulas, and you only need the first one:
- Amps = total watts ÷ 120. A display totaling 600 watts draws 5 amps.
- Watts = amps × 120, if a product states amps rather than watts.
Compare the result with 12 amps / 1,440 watts — the 80 percent continuous-load budget for a 15-amp circuit. You can run it directly in the power and wattage calculator.
What to include in the total
| Item | Include? | Note |
|---|---|---|
| Every light set on the display | Yes | Read each tag |
| Inflatable blowers | Yes | Smaller than people assume — see the inflatable power page |
| Projectors and lasers | Yes | Low draw |
| The outdoor timer or smart plug | Negligible itself | But its own amp rating caps the circuit |
| Other outlets on the same breaker | Yes | This is the one people forget |
That last row causes more surprises than anything else. Outdoor outlets are frequently on a circuit shared with a garage outlet, a bathroom, or another exterior receptacle. A space heater or a power tool on that same breaker is a large load your display is now competing with.
Why the LED difference is so large
An incandescent bulb produces light by heating a filament, and most of the energy becomes heat rather than light. An LED produces light directly. The result is that an LED set draws a small fraction of the power of an equivalent incandescent set.
In practical terms, that is why a modern whole-house display fits on one circuit and an equivalent incandescent display would not. It is also why LED sets can be chained far further end to end. See LED vs incandescent.
If you cannot find the wattage
Do not guess wildly and do not use a number from an article. The honest options are:
- Search the exact product name — the manufacturer's listing almost always carries the specification.
- Measure it. A plug-in energy meter costs little, and plugging a set into one for a minute gives you the real figure for your actual set.
- Be conservative. If a set is unmarked, unbranded and unidentifiable, treat it as an unknown load, put it on its own feed, and do not include it in a calculation that is running close to the limit.
An unidentifiable old set is also a reasonable candidate for replacement. If you cannot establish what it draws or how many may be chained, you are operating without the two pieces of information that keep a display safe.
What to buy
The products that fit the advice above, chosen by the process on our methodology page. We have not hands-on tested them; specifications are the manufacturers’ own.
Quick picks
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 |  Top pickDEWENWILS Outdoor Digital Timer, 3 outlets, 15A15 A, 3 grounded outlets, 7-day | A whole display on one schedule | 9.1 | Check price on Amazon |
| 2 |  Southwire 14/3 SJTW Outdoor Extension Cord, lighted end14/3 SJTW, 13 A rated | The standard run from house to display | 9.0 | Check price on Amazon |
#ad We may earn a commission · Prices are shown by Amazon, not by us
Scores are our own editorial judgment from published specifications and buyer feedback — not aggregated user ratings, and not from hands-on testing. See how we pick.
Jump to a full review below: power-and-timers
Common questions
How do I find out how many watts my Christmas lights use?
It is printed on a small tag on the cord near the plug, and on the box. If both are gone, search the exact product name for the manufacturer's listing, or measure it with a plug-in energy meter.
How do you convert watts to amps for Christmas lights?
Divide the total wattage by 120. A display totaling 600 watts draws 5 amps. Compare that with 12 amps, the working budget for a standard 15-amp circuit.
Do inflatables use a lot of electricity?
Less than most people assume — the blower is a small fan and the lighting is LED. They should still be included in the circuit total, along with everything else on the same breaker.
What else is on my outdoor circuit?
Often more than you expect. Outdoor outlets are commonly on a circuit shared with a garage outlet, a bathroom or another exterior receptacle. Anything plugged in there counts against the same budget as your display.
Sources
Every specification quoted on this page comes from the manufacturer’s own published information or a current retail listing, linked below. Where a figure is not published, we say so rather than estimating it.