Calculator / Wattage chart
Reference
What every type of light actually draws
Typical figures for planning. The number printed on your box beats anything on this page — products vary, and these are midpoints of a range.
Watts and amps by light type
| Type | Watts | Current | Notes |
|---|---|---|---|
| LED mini string, 100 lights | 4–6 W | 0.04 A at 120 V | The workhorse. Hundreds can share a circuit. |
| Incandescent mini string, 100 | 40–50 W | 0.38 A at 120 V | Roughly nine times the LED draw. |
| LED C9 string, 25 bulbs | 18–20 W | 0.16 A at 120 V | About 0.8 W per bulb. |
| Incandescent C9 string, 25 | 175 W | 1.46 A at 120 V | 7 W per bulb. Three sets fill a 3 A UK plug fuse. |
| LED C7 string, 25 bulbs | 13–15 W | 0.12 A at 120 V | About 0.6 W per bulb. |
| Incandescent C7 string, 25 | 125 W | 1.04 A at 120 V | 5 W per bulb. |
| LED icicle set, 300 lights | 12–18 W | 0.13 A at 120 V | Long sets, small draw. |
| Incandescent icicle, 100 | 40 W | 0.33 A at 120 V | Not 5,500 W, whatever you may have read. |
| LED net light, 4 ft × 6 ft | 10–15 W | 0.10 A at 120 V | Sized for hedges and shrubs. |
| Incandescent net light, 4 ft × 6 ft | 144–192 W | 1.4 A at 120 V | One of the heaviest common items. |
| LED rope light, per 10 ft | 8–12 W | 0.08 A at 120 V | About 1 W per foot. |
| Incandescent rope light, per 10 ft | 50–60 W | 0.46 A at 120 V | 5–6 W per foot. |
| Inflatable, small | 40–70 W | 0.46 A at 120 V | Mostly the fan, which runs continuously. |
| Inflatable, large | 100–150 W | 1.04 A at 120 V | Check the tag — they vary widely. |
| Laser or LED projector | 20–40 W | 0.25 A at 120 V | Small draw, but often on a long cord. |
How to use these
Find your type, take the wattage, multiply by how many sets you have. That total is what goes against your circuit limit.
For the chain limit, work the other way: divide the chain limit by the wattage of one set to get how many can be joined end to end. At 210 watts, a 40 watt incandescent set gives five; a 5 watt LED set gives forty-two.
Current is shown at 120 volts. At 230 volts, halve it.