How much will my Christmas lights cost to run?
Short answer: cost = watts ÷ 1,000 × hours × price per kWh. At 18 cents per kWh, 6 hours a night for 40 nights, a 40-watt incandescent mini strand costs $1.73 a season. A 100-bulb LED mini strand (9.6 W) costs about 41 cents. Add your own decorations below.
Want the full breakdown of strand types, safety and LED payback? Read our guide:How much does it cost to run Christmas lights?
1. Your decorations
Watts are from spec sheets for specific listed products. Check the box or the tag near the plug for your own number. If it lists amps only, multiply by 120.
Inflatable and projector watts are listed ratings (amps × 120 volts), likely maximums. Actual draw may be lower.
6 hours a night for 40 nights is our assumption; change it to match your timer. 18¢ is close to the U.S. Energy Information Administration's forecast 2026 average. Your bill shows your real rate: divide the total charge by the kWh used.
2. What it costs
- Watts on at once
- 161.6 W
- Per night
- 17.5¢
- For the season
- $6.98
1.3 amps at 120 volts
0.97 kWh over 6 hours
38.8 kWh over 40 nights
Circuit check: 161.6 W is 11% of the 1,440 W continuous limit on a 15-amp circuit. Anything else plugged into that circuit shares the same limit.
Also follow each strand's "max connected sets" label. For incandescent sets, CPSC advises connecting no more than three end to end.
| Decoration | Total watts | Per season | Share |
|---|---|---|---|
| 4 × LED C9 commercial strand, 25 bulbs | 80 W | $3.46 | 50% |
| 6 × LED mini strand, 100 bulbs | 57.6 W | $2.49 | 36% |
| 1 × Laser projector, rotating | 24 W | $1.04 | 15% |
How this is calculated
- Total watts = sum of watts each × how many.
- Cost per night = total watts ÷ 1,000 × hours per night × your price per kWh (18¢).
- Season cost = cost per night × number of nights.
- Circuit check: a 15-amp, 120-volt circuit supplies 1,800 W. The National Electrical Code limits loads that run 3 hours or more to 80%, or 1,440 W.
- Inflatables and projectors are rated in amps × 120 volts, likely a maximum, so real costs for them may be lower.
Example displays at 18¢ per kWh
All rows assume 6 hours a night for 40 nights. Watts are the preset values in the calculator.
| Display | Total watts | Per night | Season | 15-amp circuits needed |
|---|---|---|---|---|
| Small LED: 6 LED mini strands, 4 LED C9 commercial strands, 1 rotating projector | 162 W | $0.17 | $6.98 | 1 |
| Same layout with incandescent minis and C9s | 964 W | $1.04 | $41.64 | 1 |
| Large LED: 30 LED minis, 10 LED C9 commercial, 3 inflatables (101, 161, 432 W), 2 projectors (5 and 24 W) | 1,211 W | $1.31 | $52.30 | 1 |
| Large incandescent: same layout with incandescent minis and C9s | 3,673 W | $3.97 | $158.66 | 3 |
Switching the large display's strands to LED saves about $106 a season. In the large LED display, the three inflatables use more than half the power.
Watts used in the calculator
These come from spec pages for specific listed products. Your own strand may differ, so check its label.
| Decoration | Watts | Season at 18¢ |
|---|---|---|
| LED C7 or C9 strand, 25 bulbs | 2.4 W | $0.10 |
| LED mini strand, 100 bulbs | 9.6 W | $0.41 |
| LED C9 commercial strand, 25 bulbs | 20 W | $0.86 |
| Incandescent mini strand, 100 bulbs | 40 W | $1.73 |
| Incandescent C7 strand, 25 bulbs | 125 W | $5.40 |
| Incandescent C9 strand, 25 bulbs | 175 W | $7.56 |
| Laser projector, small / rotating | 5 W / 24 W | $0.22 / $1.04 |
| Inflatables (listed ratings) | 60 to 432 W | $2.59 to $18.66 |
Inflatable and projector ratings are amps × 120 volts, likely maximums. Size alone does not predict power: the 12 ft. cactus is rated far below the 6 ft. animated scene.
Why the calculator checks 1,440 watts
A standard 15-amp, 120-volt circuit supplies 1,800 W. The National Electrical Code treats loads that run 3 hours or more as continuous and limits them to 80%, or 1,440 W. Holiday lights running all evening count. If your total is higher, spread the decorations across more circuits. Porch lights, a garage freezer or anything else on the same circuit share that limit.
Common questions
How do I find the watts if the box lists only amps?
Multiply amps by 120 volts. A strand rated 0.08 A draws about 9.6 W.
How many strands can I connect end to end?
Follow the "max connected sets" on the label. For incandescent sets, CPSC advises no more than three, even if the label allows more.
Does a timer save money?
Yes, mostly by preventing all-night burning. Dusk to dawn in December can run about 14 hours. For the small incandescent display, a 6-hour timer saves about $55.53 a season at 18 cents.
Are inflatables expensive to run?
The ones we checked are rated 60 W to 432 W, or $2.59 to $18.66 a season at 18 cents. Their fans run the whole time they are up.
Related
- How much it costs to run Christmas lights (full guide)
- Appliance electricity cost calculator
- How much it costs to run a space heater
Sources
- U.S. Energy Information Administration: Short-Term Energy Outlook, electricity (October 2026)
- 1000Bulbs: 100-bulb incandescent mini light string (40 W)
- Novelty Lights: 100 LED wide angle mini string
- 1000Bulbs: 50 LED mini light stringer
- 1000Bulbs: 25-bulb incandescent C7 string
- 1000Bulbs: 25-bulb LED C7 string
- Christmas Central: 25-bulb incandescent C9 set
- 1000Bulbs: 25-bulb LED C9 string
- Christmas Lights, Etc: C9 commercial LED string
- The Home Depot: 12 ft. animated pre-lit inflatable (432 W)
- The Home Depot: 6 ft. animated inflatable scene
- The Home Depot: 5 ft. inflatable scene
- The Home Depot: 12 ft. inflatable cactus
- Do it Best: 5 W holiday laser projector
- Do it Best: 24 W rotating laser projector
- U.S. Consumer Product Safety Commission: Happy holidays start with safety (2025)