A standard 15-amp, 120-volt household circuit can handle about 1,800 watts total, and for lights that stay on for hours you should keep the load under about 1,440 watts (80% of capacity). That limit is per circuit, not per outlet, and several outlets often share one circuit. To find out how many holiday lights you can plug in, add up the wattage on each light string's label and keep the total under 1,440 watts. Outdoor lights should only plug into GFCI-protected outlets.
Last updated: October 2026
How do you calculate your holiday lighting load?
- Check the tag on each light string or inflatable for its wattage.
- Add up everything plugged into outlets on the same circuit.
- Keep the total under 1,440 watts on a 15-amp circuit, or under about 1,920 watts on a 20-amp circuit.
LED strings use far less power than old incandescent strings, so switching to LED is the easiest way to run more lights without tripping breakers. Also check the manufacturer's limit on how many strings can be connected end to end.
Why do outdoor holiday lights trip the breaker?
The two most common reasons are overload and moisture. Overload means too many watts on one circuit. Moisture trips the GFCI when water gets into a plug, connection or outlet cover. Valley and Antelope Valley winters are mostly dry, but winter storms, irrigation and morning dew can still soak connections. Use weatherproof "in-use" outlet covers and keep connections off the ground. If your breaker keeps tripping, read why a circuit breaker keeps tripping.
Do outdoor outlets need GFCI protection?
Yes. Outdoor receptacles are required to have GFCI protection, which cuts power within a fraction of a second if current leaks to ground, such as through water or a person. If your exterior outlets aren't GFCI-protected, or you don't have outdoor outlets where you need them, our outlet, switch and GFCI installation service can add them. Our post on GFCI vs AFCI outlets explains where each type belongs.
What holiday lighting mistakes should you avoid?
- Running extension cords through doors or windows, where they get pinched.
- Using indoor-rated cords or lights outside.
- Daisy-chaining power strips.
- Leaving lights on overnight or while away. A timer helps.
- Stapling or nailing through cords.
The U.S. Consumer Product Safety Commission publishes holiday decorating safety tips every year, and they're worth a read.
When should you call an electrician for holiday lighting?
Call if you're tripping breakers even after spreading out the load, if you need permanent outdoor outlets or a dedicated circuit for a large display, or if you want year-round outdoor landscape lighting instead of seasonal strings. B&M Electrical Services has 30+ years of experience as a licensed California contractor (C-1098584).
Frequently Asked Questions
How many LED light strings can I plug into one outlet?
It depends on each string's wattage and what else is on that circuit. Add up the watts and stay under 1,440 on a 15-amp circuit. Follow the maker's end-to-end connection limit too.
Is it safe to use extension cords for holiday lights?
Yes, if they're outdoor-rated, sized for the load, and kept out of standing water and foot traffic.
Can I add a permanent outlet for holiday lights?
Yes. A licensed electrician can install a weatherproof GFCI outlet, often on a switched or timed circuit, under your eaves or in the yard.
Want more outdoor outlets before the holidays? Call Us Today for a Free Estimate at (661) 904-9377 or schedule your service online.