NEC 210.11 / 220.14(I)
How Many Outlets on a Circuit?
The residential rule of thumb, the NEC commercial limit, and why the code sets no fixed dwelling count, for 15A and 20A circuits.
Outlets per Circuit
| Circuit | Home (rule of thumb) | Commercial (NEC max) | Total Watts | Continuous (80%) |
|---|---|---|---|---|
| 15A / 120V | 8 | 10 | 1,800 W | 1,440 W |
| 20A / 120V | 10 | 13 | 2,400 W | 1,920 W |
| 30A / 120V | 1 (dedicated) | 1 (dedicated) | 3,600 W | 2,880 W |
Home counts are the field rule of thumb (1.5A / 180 VA per outlet at 80% of the breaker), not a code maximum. Commercial counts are the hard NEC 220.14(I) limit (full-circuit VA / 180). A 30A circuit generally serves a single dedicated appliance outlet, not general receptacles.
Why the Home Answer Is a Rule of Thumb, Not a Code Limit
In a dwelling, the NEC does not limit how many receptacles go on a general-purpose branch circuit. Instead, NEC 220.12 figures the general lighting and receptacle load by floor area, at 3 VA per square foot, and NEC 210.11 requires enough circuits to carry that computed load. Because the receptacle load is baked into the area calculation, the code never assigns a per-outlet value in a home, so there is no fixed count to hit.
Electricians still need a practical number, so the trade rule allots about 1.5 amps (180 VA) per outlet and loads a circuit to 80% of the breaker: 15A x 0.8 / 1.5A is about 8 outlets, and 20A x 0.8 / 1.5A is about 10. It is conservative and keeps the circuit from nuisance tripping, but you can legally place more in a dwelling as long as the whole-house load calculation works.
In a commercial or other non-dwelling occupancy the rule is firm: NEC 220.14(I) assigns 180 VA to every receptacle outlet, so the maximum is the circuit VA divided by 180: thirteen on a 20A circuit, ten on a 15A circuit. That is a true code ceiling, not a guideline.
Frequently Asked Questions
How many outlets on a 20 amp circuit?
In a home, about 10 outlets is the common rule of thumb. The NEC does not actually limit the number of receptacles on a dwelling general-purpose branch circuit (the load is figured by floor area under NEC 220.12, not per outlet), but electricians allot roughly 1.5 amps (180 VA) per outlet and load a circuit to 80%, which gives 20A x 0.8 / 1.5A = about 10. In a commercial building the NEC 220.14(I) rule of 180 VA per receptacle sets a hard maximum of 13 on a 20A circuit.
How many outlets on a 15 amp circuit?
About 8 in a home by the common rule of thumb (15A x 0.8 / 1.5A = 8). As with a 20A circuit, the NEC sets no fixed dwelling limit; the count is a practical guideline. In a commercial space the NEC 220.14(I) 180 VA-per-receptacle rule caps a 15A circuit at 10 receptacles.
How many receptacles on a 20 amp circuit per NEC?
For a non-dwelling (commercial) occupancy, NEC 220.14(I) assigns 180 VA to each receptacle outlet. A 20A / 120V circuit is 2,400 VA, so 2,400 / 180 = 13 receptacles maximum. A 15A circuit is 1,800 VA, giving 10. Dwelling units are exempt from this receptacle count because their receptacle load is included in the 3 VA per square foot general lighting load of NEC 220.12.
How many watts can an outlet handle?
A single 15A / 120V receptacle can carry up to 1,800 watts and a 20A receptacle up to 2,400 watts, but that is the whole circuit's capacity, not per outlet, and continuous loads are limited to 80% (1,440 W on 15A, 1,920 W on 20A). In practice you spread the load across the circuit's outlets rather than pulling the full rating from one. A standard duplex receptacle is rated 15 or 20 amps.
Does the NEC limit how many outlets are on a circuit?
In dwellings, no. NEC 210.11 and 220.12 figure the receptacle and lighting load by floor area (3 VA per square foot) and require a minimum number of circuits, but they do not cap outlets per circuit. In non-dwelling occupancies, NEC 220.14(I) effectively limits the count by assigning 180 VA to each receptacle. The dwelling rule of thumb (8 on 15A, 10 on 20A) is good practice, not a code maximum.
How many lights can I put on a circuit?
Add up the actual wattage of the fixtures and keep the total under 80% of the circuit: 1,440 watts on a 15A circuit, 1,920 watts on a 20A circuit. With modern LED fixtures at 10 to 15 watts each you can run dozens; with older high-wattage fixtures far fewer. Lighting and receptacles often share a general-purpose circuit in a dwelling, so count both against the same budget.
Related Calculators
Load Calculator
The NEC dwelling load calculation (220.12 area method) that decides how many circuits you need.
Wire Size Calculator
The conductor for a 15A or 20A circuit per NEC 310.16, with temperature derating.
Box Fill Calculator
Whether your device box has room for the conductors, devices, and grounds (NEC 314.16).