I want to put lights in plugs in my garage. How many lights can you put and connect together for one switch?

I like to use normal bulbs, what size breaker can you use?

I would like to have at least 4 lights on one switch to turn on or off at the same time.

We have two sides, I would like to put 2 lights in the back of one side and two up front, that should be a normal hook up.

I am only putting lights on the breakers, so for the one can you hook up to 4 lights on one switch to one breaker. Then the other side, where I want two lights in the back and two up front, can these 4 go to one breaker also?

  • Hi there, Your question is a bit unclear so lets try to clear it up. You would like to have 4 lights controlled by one switch, and than another 2 lights controlled by another switch? Is that right? As a general practice we usually use #14 AWG wire and a 15 amp breaker to do that. On a 15 amp breaker you can have up to 12 devices. A device would be a light or a receptacle (the switch does not count as a device since it doesn't consume power). So if you just wanted 6 lights ( 6 devices) than yes you can do that all from one 15 amp breaker. Oct 26, 2016 at 9:23
  • I'm guessing "normal bulbs" means old-fashioned 19th-century incandescent tungsten-filament bulbs of the sort Thomas Edison would have recognized, not something 21st-century like LEDs. So nominal 100W per fixture. Oct 26, 2016 at 10:08
  • Ur right on what I was asking ( but I like to run only 4 lights on one breaker and have a light switch to control these 4 lights at the same time) now on the two lights ( I like to have four lights total on the other side of the garage and a switch that controls two lights at one time now these four lights ur saying can be on the same breaker or not) I was wanting one breaker per 4 lights (((( on light bulbs I do like the iridescent I guess the reqular tear drop shaped bulbs Oct 27, 2016 at 9:48

2 Answers 2


A 120 volt, 15 ampere circuit can provide 1800 watts (unless it's a "continuous load", then only 1440 watts). I'd guess that a "normal bulb", is a 60 watt incandescent bulb. Which means you can have up to 30 bulbs on a 15 ampere circuit (likely a bit less to compensate for losses elsewhere in the circuit).

120 volts * 15 amperes = 1800 watts
1800 watts / 60 watts = 30 bulbs

However, the National Electrical Code says that "An outlet supplying luminaire(s) shall be calculated based on the maximum volt-ampere rating of the equipment and lamps for which the luminaire(s) is rated." (220.14(D)). So you'll have to check the rating on the fixtures you're installing, and do the calculations based on those values.

Having said all that... You should have no problem supplying 8 light fixtures from a single 120 volt 15 ampere circuit, unless the fixtures have four or five bulbs each.

  • I was talking about 100 watt light bulbs and yes iridescent ones or normal bulb can you safely do four light fixtures with two lights each on one 15 amp breaker is what you are saying but can one light switch (one that only turns on and off with a flick) control all 4 lights or just two lights Oct 27, 2016 at 9:47
  • @MatthewPerry a switch can control as many lights as are on the circuit, as long as the current drawn by the bulbs is less than the rated current of the switch.
    – Tester101
    Oct 27, 2016 at 9:50
  • OK so 15 amp can do 4 light fixtures and the 4 fixtures can hold 2 bulbs each and be good right Oct 27, 2016 at 9:56
  • Yes. Eight 100 watt bulbs is 800 watts, which is well below the 1800 watt capacity.
    – Tester101
    Oct 27, 2016 at 12:24
  • OK so how would you wire this up from the breaker box u would have one wire coming from it to the light switch then how would you do the light fixtures Oct 27, 2016 at 18:41

Technically the question should have been asked a bit differently. First one shoild understand that an electrical circuit comprised of a 15Amp breaker should not be loaded more than 80% of its rating capacity under continuous load. In this case this 15A breaker has a rating capacity of 15Amps. Continuous load is considered a load operating continuouly for 3 hours or more. In this case the circuit should not be loaded over 12 Amps if the total load connected to it will operate for 3 hours or more. Knowing this one could roughly calculate how many watts this 15A circuit could safely handle by multiplying the amperes by the voltage. 12A x 120V = 1440Watts. With a capacity of 1440 watts one could safely operate 14 light bulbs of 100 watts each. And this is if you planned to keep these 14 lamps turned on for 3 hours or more.

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