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How many outlets on a 15 amp circuit?
How many outlets on a 15 amp circuit, how many watts, which wire: what Québec’s Code allows on a single circuit, and when you need another one.
In short
This guide covers the capacity of a single 15 amp circuit: how many outlets it can supply, how many watts, and on what wire.
- The 2021 Canadian Electrical Code, in force in Québec since March 26, 2026, allows 12 outlets on a 15 A circuit, or 15 if the breaker is marked for continuous operation at 100%.
- A duplex receptacle counts as one outlet.
- On an arc-fault protected circuit, Québec sets the limit at 10 outlets.
- At 120 V, a 15 A circuit delivers 1,800 W.
- Under Rule 14-104 of the Canadian Electrical Code, No. 14 copper wire is protected at 15 A at most; No. 12, at 20 A.
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What a 15 amp circuit powers
In a home, the 15 A circuit is the ordinary circuit: 5-15R receptacles are protected at 15 A at most, and so are the lighting circuits of a dwelling (2018 edition).
Since March 26, 2026, the Québec Construction Code, Chapter V (Electricity), incorporates the 25th edition of the Canadian Electrical Code, with Québec amendments.
The previous edition can still apply to work that started before October 17, 2027.
Some appliances don’t share their circuit: the refrigerator and the microwave oven, for example, each have a dedicated branch circuit in the 2018 edition of the Code. The details are in our guide on dedicated circuits.
The kitchen also has its own rules: at the counter, under the 2026 Code, no more than two receptacles per circuit and no other outlet on those circuits, with some exceptions. See our guide on kitchen counter outlets.
How many outlets on a 15 amp circuit
Rule 8-304 of the Canadian Electrical Code sets the maximum number of outlets on a 2-wire branch circuit. Since the 2021 edition, it takes into account the circuit rating and the breaker’s marking.
| Circuit | Breaker marked for continuous operation at | Maximum outlets |
|---|---|---|
| 15 A | 80% | 12 |
| 15 A | 100% | 15 |
| 20 A | 80% | 16 |
| 20 A | 100% | 20 |
For this count, a duplex receptacle counts as one outlet, a triplex as 1.5 and a quadruplex as 2.
When the connected load is known, the number of outlets can go over this maximum, as long as the current doesn’t exceed the marking of the breaker protecting the circuit.
In earlier editions, the limit was 12 outlets, whether the circuit was 15 A or 20 A.
Québec doesn’t amend this rule; it only adds a lower limit for arc-fault circuits.
Watts and lights
At 120 V, a 15 A circuit delivers 1,800 W.
According to the Régie du bâtiment du Québec (2018 edition), a continuous load, such as heating, is limited to 80% of the breaker rating, unless the breaker is marked for 100%: on a 15 A circuit at 120 V, that’s 1,440 W.
For lighting, what counts is the total wattage of the fixtures on the circuit, which is protected at 15 A at most in a dwelling (2018 edition). To add up watts or convert them to amps, use our watts to amps calculator.
Wire size
Under Rule 14-104 2) of the Canadian Electrical Code, the wire size sets the breaker allowed: 15 A at most for No. 14 copper wire, 20 A for No. 12 and 30 A for No. 10.
So No. 14 wire is never protected by a 20 A breaker: that would protect it above what the Code allows.
In NMD90 cable from the manufacturer Nexans, the jacket helps you recognize the size: white for No. 14, yellow for No. 12, orange for No. 10. A blue No. 14 jacket is used for bedroom outlets connected to an arc-fault breaker.
According to a Code specialist, the 2021 change could increase the use of 20 A breakers, No. 12 cables and 5-20R T-slot receptacles.
Outlets to add?
Before adding a circuit, we check that the panel can take it. The price is in the written quote, at no charge.
Send my quote requestArc-fault circuits: 10 outlets at most
In Québec, the number of outlets on a branch circuit with arc-fault protection must not exceed 10, notwithstanding Rule 8-304. That is Rule 26-658 4) of the 2026 Code.
Adding an outlet to an older circuit without arc-fault protection doesn’t require protecting the whole circuit: an arc-fault receptacle installed as the first added outlet is enough.
The details, including the rooms where this protection is required, are in our guide Arc-fault breaker: where the Code requires it.
When it’s too much
When a circuit draws more than its capacity, that’s an overload, and the breaker cuts the power.
Example: a space heater adds to what is already running on the same circuit, and the total goes over its rating. Plug it into another circuit. If it keeps happening, an electrician can add a circuit.
The other causes of a tripping breaker are in our guide Breaker keeps tripping: the causes and what to do.
Adding an outlet or a circuit is an electrician’s job: according to the Corporation des maîtres électriciens du Québec, electrical work of any kind is reserved for electrical contractors.
Our master electricians add, move or replace outlets. Before adding a circuit, we check that the panel can take it. A breaker that keeps tripping because of an overload may also call for one more circuit.
Frequently asked questions
How many outlets on a 15 amp circuit?
Under the 2021 Canadian Electrical Code, in force in Québec, 12 outlets if the breaker is marked for continuous operation at 80%, 15 if it is marked for 100%. A duplex receptacle counts as one outlet.
How many watts on a 15 amp circuit?
At 120 V, 1,800 W. For a continuous load such as heating, the limit is 80% (2018 edition), or 1,440 W, unless the breaker is marked for 100%.
15 amp or 20 amp circuit?
A 20 A circuit needs at least No. 12 copper wire, and it can supply more outlets: 16 or 20 depending on the breaker’s marking, compared with 12 or 15 for a 15 A circuit.
Can I put a 20 amp breaker on my 15 amp circuit?
Not on No. 14 wire: under Rule 14-104 of the Canadian Electrical Code, its protection is 15 A at most.
Can an arc-fault circuit have 12 outlets?
No. In Québec, a branch circuit protected against arc faults can’t supply more than 10 outlets.
Can an outlet be added to an existing circuit?
Yes, if the circuit allows it. On an older circuit without arc-fault protection, it’s enough for the first outlet added to be an arc-fault receptacle; the rest of the circuit then doesn’t need it (2026 Code). And it’s an electrician’s job.
Outlets to add, or a circuit that keeps tripping?
We check that the panel can take the circuit, and the price is in the quote.
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Sources
Consulted on October 30, 2026.
- Gazette officielle du Québec, March 11, 2026, Order in Council 236-2026 (Construction Code, Chapter V) (in French)
- Construction Code (LégisQuébec), Section 5.01 (in French)
- Régie du bâtiment du Québec, Quality control of electrical installation work (in French)
- Electrical Industry News Week, Changes to the 2021 Canadian Electrical Code Part 1: Section 8
- IAEI Magazine, When is overcurrent protection required for current-carrying conductors?
- Nexans, CANADEX NMD90 Copper