Let’s say you have a 15 amp, 20 amp, or a 30 amp circuit. *How many outlets can you put on these circuits?* Usually, when we encounter these questions, we consult a relevant NEC article.

The closest guideline to how many outlets can you put on 15A, 20A, or 30A circuits is found in the **NEC 210.21** Chapter titled ‘Outlet devices’. This NEC chapter includes a table that specifies circuit ratings, acceptable ratings, and maximum load such a circuit can handle.

This is the *‘210.21(B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle’* NEC table:

Circuit Rating (Amps): |
Receptacle Rating (Amps): |
Maximum Load (Amps): |

15 Amp Circuit |
15 Amp Receptable | 12 Amps |

20 Amp Circuit |
20 Amp Receptable | 16 Amps |

30 Amp Circuit |
30 Amp Receptable | 24 Amps |

You may be wondering: “Well, where does it list the number of outlets I should put on the 15 amp, 20 amp, or 30 amp circuit?”

As you can see, the NEC guidelines do not specify the number of outlets you can put on an outlet directly. This is done indirectly by specifying the maximum load you can put on a 15A, 20A, or 30A circuit.

So, in order to figure out how many outlets can be put on a circuit, we have to:

- Stop thinking about the number of outlets or receptacles.
**Start thinking about how many amps do these outlets or receptacles draw.**

*Example:* A 20 amp circuit has a specified maximum load of 16 amps. That means that you can put on outlets that will power devices with no more than 16 amps; we are talking about a **combined amp draw of 16A** (for a **total wattage of 1,920W** for 120-volt outlets). If a receptacle has a 16 amp draw, you can put on 1 receptacle. If it has 18 amps, you can’t put it on; 0 receptacles. If it has a 1 amp draw, you can put on 16 of them.

This is how you can use the instructions listed in the NEC 210.21 table to figure out how many outlets you can put on a circuit. In practice, this *‘you can only put 16 amps on 20 amp circuit’* is known as **NEC 80% rule**. Namely, this is a security measure; if you would put a 20 amp receptacle on a 20 amp circuit, you would risk the circuit catching on fire.

Understanding this NEC 80% rule, we can quite precisely tell how many outlets to put on 15 amp, 20 amp, and 30 amp circuits if we know the amp draw of the receptacles. Further on, you will find 3 outlet number tables detailing the following:

**How many lights and outlets on a 15 amp circuit?**A good rule of thumb is to put a**maximum of 8 outlets**on a 15 amp circuit. The 15 amp outlet chart below tells you when you should put*1, 2, 4, 6, 8, or 12 outlets*on a 15A circuit.**How many outlets can you put on a 20 amp circuit?**A good rule of thumb is to put a**maximum of 10 outlets**on a 20 amp circuit. The 20 amp outlet chart below tells you when you should put*1, 2, 4, 8, 11, 12, and 16 outlets*on a 20A circuit.**How many outlets can you put on a 30 amp circuit?**A good rule of thumb is to put a**maximum of 16 outlets**on a 30 amp circuit. The 30 amp outlet chart below tells you when you should put*1, 2, 3, 4, 6, 8, 12, 16, and 24 outlets*on a 30A circuit.

First, however, let’s look at how to think about connecting this amp draw with the number of outlets:

### How Many Amps Per Outlet? This Determines The Number Of Outlets Per Circuit

To answer how many outlets per circuit, we first need to answer how many amps per outlet. We will also explain how many watts per outlet we can get or should aim for.

From the NEC 210.12(B)(2) table we can clearly see that the 15A breaker can handle 12 amps, the 20A breaker can handle 16 amps, and the 30A breaker can handle 24 amps. At 120 volt, this will produce the maximum wattage of 1,440W, 1,920W, and 2,880W, respectively.

Now, the real question is how many amps do different electric devices we will connect to the outlets draw.

Examples for 120V electric circuits:

- A
**40W**LED light will draw**0.33 amps**. - A big
**120W**house fan will draw**1 amp**. - A
**240W**42-inch plasma TV will draw**2 amps**. - A
**360W**laptop with extra desktop will draw**3 amps**. - A
**1,000W**waffle iron will draw**8.33 amps**. - A
**1,500W**electric space heater will draw**12.5 amps**.

This is all good and right, but when we are installing our circuits and outlets, we don’t exactly know what electric devices we will run through our outlets.

With the average amp draw from each outlet unknown, we help ourselves by using this simple rule of thumb:

**1.5 amps per outlet.**

In short, we presume every outlet will draw about 1.5 amps (that’s 180 watts at 120V). With that in mind, we can easily calculate how many amps we should put on any circuit.

*Example:* How many amps should you put on a 15 amp circuit?

Here we use two directions, namely:

- NEC table that tells us that we can put at most 12 amps on a 15A circuit.
- Outlet amps rule of thumb that tells us we should calculate 1.5A per outlet.

The calculation of the number of amps on this 15A circuit looks like this:

**Number Of Outlets (15A)** = Maximum Allowable Amp Draw / 1.5A Per Outlet = 12A / 1.5A Per Outlet = **8 Outlets**

We can see that it is recommended to put about 8 outlets on a 15A circuit. That, of course, doesn’t mean we can’t put 1, 2, 4, or even 12 outlets on a 15A circuit. The same is true for 20 amp and 30 amp circuits.

To help you out, you can use these outlet number tables for 15A, 20A, and 30A circuits that will tell you how many outlets you can put on a circuit, given different average electric device amp draws:

## How Many Outlets On A 15 Amp Circuit:

A 15 amp circuit has the maximum amp draw of 12A, for a total wattage of 1,440W at 120V. Here is how many outlets you can put on a 15A breaker, given the average amps draw. We have also calculated how many watts can an individual outlet handle if all of them are powering electric devices at the same time:

Device Amp Draw (Average): |
Number of Amps: |
Wattage Per Device (120V): |

1 Amp | 12 Outlets | 120 Watts |

1.5 Amps | 8 Outlets | 180 Watts |

2 Amps | 6 Outlets | 240 Watts |

3 Amps | 4 Outlets | 360 Watts |

6 Amps | 2 Outlets | 720 Watts |

12 Amps | 1 Outlet | 1,440 Watts |

Practically, we apply the 1.5 amps per outlet rule of thumb. This means that we standardly put **8 receptacles on a 15 amp circuit.**

## How Many Outlets On A 20 Amp Circuit:

A 20 amp circuit has the maximum amp draw of 16A, for a total wattage of 1,920W at 120V. Here is how many outlets you can put on a 20A breaker, given the average amps draw. We have also calculated how many watts can an individual outlet handle if all of them are powering electric devices at the same time:

Device Amp Draw (Average): |
Number of Amps: |
Wattage Per Device (120V): |

1 Amp | 16 Outlets | 120 Watts |

1.5 Amps | 11 Outlets | 180 Watts |

1.6 Amps | 10 Outlets | 192 Watts |

2 Amps | 8 Outlets | 240 Watts |

4 Amps | 4 Outlets | 480 Watts |

8 Amps | 2 Outlets | 960 Watts |

16 Amps | 1 Outlet | 1,920 Watts |

Practically, we apply the 1.5 amps per outlet rule of thumb. This means that we standardly put **11 receptacles on a 20 amp circuit.**

## How Many Outlets On A 30 Amp Circuit:

A 30 amp circuit has the maximum amp draw of 24A, for a total wattage of 2,880W at 120V. Here is how many outlets you can put on a 30A breaker, given the average amps draw. We have also calculated how many watts can an individual outlet handle if all of them are powering electric devices at the same time:

Device Amp Draw (Average): |
Number of Amps: |
Wattage Per Device (120V): |

1 Amp | 24 Outlets | 120 Watts |

1.5 Amps | 16 Outlets | 180 Watts |

2 Amps | 12 Outlets | 240 Watts |

3 Amps | 8 Outlets | 360 Watts |

4 Amps | 6 Outlets | 480 Watts |

6 Amps | 4 Outlets | 720 Watts |

8 Amps | 3 Outlets | 960 Watts |

12 Amps | 2 Outlets | 1,440 Watts |

24 Amps | 1 Outlet | 2,880 Watts |

Practically, we apply the 1.5 amps per outlet rule of thumb. This means that we standardly put **16 receptacles on a 30 amp circuit.**

With these tables, you can pretty accurately check how many outlets you can put on different home circuits. If you have any questions about this, use the comments below and we’ll try to help you out.

Thks. So my downstairs bedrooms are either 15 or 20 amp breakers. you can’t just change breakers from 15 to 20 can you? Don’t you need different wiring and thus you can’t change size of breakers. I have one space heater that is rated at 1500 watts. If you just set it for say 70 degrees, does it use 1500 watts to work or what. I have guests coming and I have furnace air going into these rooms but it is chilly (in Utah) and so I use the heater to help out now and then. Any comments?

Hi Ozzie, if you upgrade from 15A to 20A breaker, you will possibly have to change the wires as well. Namely, 15A might have an 18 AWG copper wire, but a 20A might have a 14 AWG copper wire. It might be that the existing 15A breaker does have a 14 AWG wire, you will need to check that.

The 1500W heater, when operating at 100% output, will pull 12.5A on a 120V circuit; that will require a 20A breaker (15A is too small due to the 80% max. load rule). Usually these 1500W heaters have 3 heating modes; 900W, 1200W, and 1500W. If you set it on the highest heating mode, the 15A breaker won’t be to handle that. However, if you set it to Low or Medium setting, even the 15A breaker will be able to handle that. Hope this helps.