How Many Outlets Can You Put on One Circuit?
You want to add an outlet, or you are wondering why one circuit keeps tripping. Either way the question is the same. How many outlets can one circuit safely run?
The short answer for a typical Ontario home is up to 12 outlets on a standard 15 amp circuit. But the real answer depends on what those outlets power. Here is how it works and where the limits come from.
The General Rule
A common guideline puts up to 12 outlets on a 15 amp circuit and up to 13 on a 20 amp circuit. The logic is the 80 percent rule. You load a circuit to no more than 80 percent of its rating for safety, and each outlet is estimated at a modest draw. That math lands around 12.
This applies to general use outlets in living rooms, bedrooms, and hallways. Outlets that feed heavy appliances follow stricter rules.
| Circuit size | Typical max outlets |
|---|---|
| 15 amp | up to 12 |
| 20 amp | up to 13 |
The 80 Percent Rule
A 15 amp circuit can carry 15 amps, but you size continuous loads to 80 percent of that, which is 12 amps. Staying under that line keeps the wire from running hot. Pack too many devices on one circuit and you cross the limit, which trips the breaker or overheats the wire.
When the Limit Drops
Some areas and devices need their own circuit or a much lower outlet count.
Kitchens and High Draw Appliances
Kitchen counter outlets carry heavy loads from kettles, microwaves, and toasters. Code requires dedicated or split circuits for them, not a string of 12 outlets. A microwave, a fridge, a dishwasher, and a washer often each need their own circuit.
Dedicated Circuits
Large or continuous loads get their own circuit with nothing else on it. That includes EV chargers, hot tubs, air conditioners, and electric ranges. If you are adding one of these, do not tap an existing outlet circuit. See our EV charger guide for an example.
Signs a Circuit Is Overloaded
Too many outlets pulling too much shows up fast. Watch for breakers that trip often, warm outlet covers, dimming lights when an appliance starts, or a buzzing sound. If your breaker keeps tripping, read our guide on why your breaker keeps tripping.
Overloading is not just inconvenient. It runs wires hot, and heat is how electrical fires start. The Electrical Safety Authority links 143 electrical related fatalities in Ontario between 2015 and 2024, and its 2024 Ontario Electrical Safety Report found that electrical fatalities outside of work rose 40 percent over the past decade.
Patience Cathcart, the ESA Public Safety Officer, said the findings show why safety has to reach beyond job sites, and that the agency stays focused on "educating the public, guiding industry."
Adding Outlets Safely
Counting outlets is the easy part. Knowing whether your circuit and panel can take more is the job of a licensed electrician, who checks the wire gauge, the breaker size, and the existing load. In Ontario, the ESA states a Licensed Electrical Contractor is the only business you can legally hire to add circuits or outlets. We handle this through our residential electrical services, and if your panel is full, our circuit breaker replacement work can help.
Outlets Per Circuit FAQ
How many outlets can be on a 15 amp circuit?
A typical Ontario home runs up to 12 general use outlets on a 15 amp circuit, based on the 80 percent rule. High draw areas like kitchens need fewer outlets or dedicated circuits.
How many outlets can be on a 20 amp circuit?
Up to about 13 general use outlets on a 20 amp circuit. As with 15 amp, kitchens and heavy appliances follow stricter rules.
Can lights and outlets share a circuit?
They can in general use areas, but mixing them means a tripped breaker takes out both your lights and your outlets at once. Many electricians keep them separate.
How do I know if a circuit is overloaded?
Frequent trips, warm outlets, dimming lights, or buzzing all point to overload. An electrician can measure the load and tell you if you need another circuit.
Does each appliance need its own circuit?
Large or continuous loads do, like EV chargers, ranges, and hot tubs. General devices can share a circuit within the outlet limit.
The Bottom Line
Up to 12 outlets on a 15 amp circuit is the rule of thumb for general use. Kitchens and heavy appliances need fewer outlets or their own circuits. If a circuit trips, runs warm, or you want to add outlets, have a licensed electrician check the load before you add anything.
Need more outlets or a new circuit?
Kolji Bros. Electrical adds outlets and circuits safely for homes and businesses across the GTA. Call 1 866 565 5427 or book online.