How Many Halloween Projectors and Party Lights Can You Run on One Circuit?
By the amps, dozens. A small LED Halloween projector draws about 0.05 amps, so a 15-amp circuit could in theory carry well over a hundred of them. That is never the number that stops you. You run out of outlets to plug them into, and out of sensible places to keep them dry and on a ground-fault (GFCI) outlet, long before you run out of amps. The amps only start to matter the moment a real load joins the party, a fog machine, an inflatable, or a big video projector. Here is how to think about loading one circuit, and the worked example that shows where it finally gets tight.
Adding up a mixed yard, projectors plus a fogger plus string lights? Drop the watts and amps into the Continuous Load Calculator to check the total against the circuit's all-evening limit.
Start with the per-light draw
Nearly every Halloween projector and party light sold today is LED, and LED is why these are such small loads. The amps are just the watts on the label divided by 120 volts. Current (2026) figures:
| Device | Watts | Amps at 120V |
|---|---|---|
| Small LED pattern / laser projector | 4 to 10 W | 0.03 to 0.08 A |
| LED party / disco light | 10 to 60 W | 0.08 to 0.5 A |
| Bright LED video projector | 100 to 200 W | 0.8 to 1.7 A |
| Home fog machine | 400 to 1,000 W | 3.3 to 8.3 A |
The split is enormous. A yard projector and a fog machine are both "Halloween stuff you plug in," but the fogger pulls well over a hundred times the current. That gap is the whole story of loading a circuit: a pile of little projectors is nothing, and one fogger is almost everything.
Why amps are not the limit on the little ones
A 15-amp circuit is held to 80 percent of its rating for a load left on all evening, which is 12 amps of room. A 20-amp circuit gives 16. Line the small projectors up against that ceiling:
Small LED projectors: 12 A ÷ 0.05 A = 240 of them
15-amp circuit continuous ceiling: 15 × 0.80 = 12 A
20-amp circuit continuous ceiling: 20 × 0.80 = 16 A
You are not going to hang 240 projectors. You will run out of outlets first. A wall receptacle has two plug slots; an outdoor three-outlet cord gives you three; a six-outlet outdoor power block gives you six. Every one of those still has to be outdoor-rated and sitting on a GFCI, and every junction still has to stay dry. So the honest limit on a circuit of nothing but small projectors is how many you can plug in and keep safe, which is a handful per outlet, not the 240 the amps would allow.
Where the amps come back: a worked yard
The arithmetic changes the moment a heavy load lands on the same circuit. Take a realistic corner of a yard sharing one 15-amp circuit:
Six small LED projectors: 6 × 6 W = 36 W → 0.30 A
One bright video projector: 150 W → 1.25 A
Running subtotal: 186 W → 1.55 A
Add one 1,000-watt fog machine: +1,000 W → +8.33 A
New total: 1,186 W → 9.9 A (ceiling is 12 A)
All the lights together were a single amp and a half. The one fogger nearly filled the circuit by itself and pushed the total to 9.9 amps, close enough to the 12-amp ceiling that a second fogger, or an inflatable blower with its startup surge, would tip it over. That is the pattern every time: add up the little lights for completeness, but watch the foggers, the inflatables, and the incandescent string lights, because those are the loads that actually fill a circuit.
A plan that keeps one circuit happy
- Count outlets, not amps, for the small lights. A handful of projectors and party lights per outdoor-rated, GFCI-protected outlet is the real cap.
- Give every heavy load its own circuit. A fog machine or a big inflatable wants to be the main thing on its circuit, not sharing with much else.
- Keep each circuit's all-evening total under 12 amps on a 15-amp circuit, or 16 on a 20-amp. Add the watts, divide by 120, compare.
- Spread the display across circuits once the total climbs. Two outdoor outlets often sit on two different breakers; mapping them is covered in how to tell which outlets share a circuit.
NEC reference
National Electrical Code (NEC) 2020. A holiday display left on all evening is a continuous load, so the branch circuit is held to 80 percent of its rating: 12 amps on a 15-amp circuit, 16 on a 20-amp (210.19(A) and 210.20(A); continuous load defined in Article 100). Outdoor receptacles require GFCI protection under 210.8(A)(3). The wattage figures are typical 2026 product-label values; the labels on your own gear govern.
Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.
For the whole season
The Holiday Electrical Safety Handbook
This guide answers one question. The Handbook covers Halloween through New Year's: how many amps a circuit can really carry (a 15 amp breaker means 12 amps, a 20 means 16), extension cords, GFCI outlets, outdoor displays in the weather, the Thanksgiving kitchen, tree lights, space heaters, and what to do when something goes wrong. Every figure is pre-converted to amps, so you add instead of calculate.
Get the next seasonal safety check by email
Optional. Short emails before each holiday, written for homeowners.
Related
- Holiday Circuit Map and Load Worksheet (free PDF): a fill-in circuit map for your own house plus six one-page seasonal safety cards, with every load already converted to amps.
- How Many Amps Does a Halloween Party Light Use?: where the per-light 0.05-amp figure in this example comes from, and the adapter number that fools people.
- How Many Amps Does a Whole Halloween Display Use?: the same add-up-the-amps method for a full yard, split across more than one circuit.
- Continuous Load Calculator: check a running total against the 80 percent all-evening ceiling for the circuit.