What is a 15-amp Circuit Breaker Used for?

A 15 amp breaker is used to protect light bulbs and small appliances from faulty electrical currents.

They are common in bedrooms and living rooms, usually on a 15-amp circuit.

15 Amp circuit breakers protect smaller appliances from overcurrent and short circuits.

If you want to install the device in your home, make sure you know how to balance the load capacity.

You will also need to follow the manufacturer’s guidelines and the National Electric Code limit to avoid overloading the electrical system.

Which brand is best for your needs?

There are different brands of breakers and each has its strength. Your choice will depend on the project you want to carry out.

For a top quality industrial project, you can go for high-quality but expensive Square D QO breakers, and Siemens products for smaller residential work.

But you should always go for laboratory tested equipment to ensure your safety and functionality.

Below are some notable brands on the market:

  • Square D homeline circuit Breakers
  • Cutler hammer
  • Siemens Breakers
  • Murray circuit breaker
  • FPE Circuit breaker and so forth

How many watts can the 15-amp breaker handle?

how many watts can the 15-amp breaker handle

The maximum wattage a 15 amp receptacle can carry before tripping is 1800 watts.

However, you will need to observe the NEC guidelines to be on the safest side.

To achieve this, first calculate the wattage of the receptacle by multiplying the ampere with the voltage.

Calculate the wattage of your breaker

Since the rating for all breakers is in Ampere and loads in wattage, you will need to convert 15 amps to watts.

To achieve this, apply Ohm’s law formula for converting amps to watts, which is: Amperage (A) x Volts = Watts (W).

Therefore, 15A X 120 Volt = 1800 watts.

National Electrical Code and Outlets

The NEC did not limit the number of outlets per circuit. But, they stated that circuits cannot supply over 80% of the circuit breaker limit.

This regulation is called the maximum continuous load, and it ensures the breaker doesn’t trip continuously during use.

To get the 80% of 1800 watt, multiply 1800 by 0.8 you will get 1440 watt.

So the maximum watt a 15-amp circuit can safely handle is 1440 watts.

From this now, you can easily calculate the number of bulbs a 15-amp line can carry.

For example, assuming you want to install an incandescent bulb of 100 watts on a 15A circuit, you can calculate the maximum number to install by dividing 1400W by 100W. This will give you 14 bulbs.

So the maximum bulbs a 15A circuit can handle are 14.

How many outlets can the 15-amp breaker support?

A 15-amp receptacle can safely support 8 outlets. You can still plug more outlets into the breaker, but the rule is 1 outlet per 1.5 amps.

And going by the rule of law which recommends 80% or less load for circuit breakers, you discover that the maximum outlets a 15-amp circuit can carry are 8.

Wire gauge for 15A circuit breaker

The 15 Amp receptacle will require a 14-gauge wire size for optimum performance and protection. Using the wrong gauge of wire can lead to circuit overload and fire outbreaks.


Though there is no direct rule on the number of outlets a 15A circuit can handle, you should not use over 1440 watts at a time.

The rule of thumb is 1.5 amps per outlet, and the circuit should not supply over 80% of the breakers limit to avoid constant tripping.

So with 15 amp breakers, we recommend a maximum of 8 outlets. Hope the article was helpful?

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About mariaelectricals

Hi, I am Emmanuel Nwankwo, a commercial electrician and the founder of mariaelectricals.com. I established this blog to share my seven years of work experience in electrical installations and repairs.