How many lights on a 15 amp circuit?
A 15 amp lighting circuit runs 1,440 watts of lights when sized at 80% of its rating, the conservative assumption that the lights stay on for hours: 24 fixtures of 60 W or 160 LED bulbs of 9 W.
Lights on 15 and 20 amp circuits by fixture wattage
| Fixture | 15 A circuit | 20 A circuit |
|---|---|---|
| 9 W LED bulb | 160 | 213 |
| 13 W CFL | 110 | 147 |
| 60 W incandescent | 24 | 32 |
| 100 W incandescent | 14 | 19 |
How the number of lights on a 15 amp circuit is calculated
Lights = breaker amps × 120 V × 0.8 ÷ watts per fixture. 15 A × 120 V × 0.8 = 1,440 W; 1,440 W ÷ 60 W = 24 fixtures of 60 W.
What limits a 15 amp lighting circuit
This page sizes lighting as a continuous load, one that can run for three hours or more, and so counts 80% of the breaker rating. That is a conservative planning assumption, not a code rule for every home lighting circuit. Use the wattage the fixture actually draws, printed on the LED bulb or driver, not the “equivalent” incandescent wattage on the box.
Dimmers, transformers for low-voltage lighting and fixtures with built-in fans draw more than the lamp alone. Count them by their nameplate.