How many receptacles a room needs is set by the electrical code. In the United States, most states adopt the National Electrical Code (NEC), published by the NFPA, sometimes with local amendments. This calculator applies its spacing rules to estimate the minimum count for a room.
Living rooms, bedrooms, family and dining rooms
The NEC rule in section 210.52(A) is that no point along the floor line of a wall may be more than 6 ft from a receptacle. In practice, a receptacle every 12 ft of wall meets it. In addition:
- every wall space 2 ft or wider needs coverage, including short walls between doors;
- doorways, fireplaces and fixed cabinets break the wall line, so measure only the usable wall;
- a floor receptacle counts only if it is within 18 in of the wall.
The calculator counts one receptacle per started 12 ft of usable wall. Draw the room and place them so the 6 ft rule holds at every point, especially near corners and doors.
Kitchens
- Countertops: every counter space 12 in or wider needs a receptacle, and no point along the counter wall may be more than 24 in from one, which works out to about one every 4 ft.
- Islands and peninsulas: since the 2023 NEC, receptacles on islands are no longer required, but the code asks for provisions so they can be added later. Enter any you plan to install.
- Circuits: at least two 20 A small-appliance circuits serve the counter receptacles.
- GFCI: recent editions require ground-fault protection for all kitchen receptacles.
Bathrooms
At least one receptacle within 3 ft of each basin, on a 20 A circuit, with GFCI protection. One receptacle placed between two basins can serve both.
Hallways
A hallway 10 ft or longer needs at least one receptacle.
Example
A kitchen with 20 ft of usable wall and 14 ft of counter needs 2 wall receptacles and 4 counter receptacles: 6 in total, on at least two 20 A small-appliance circuits.
Circuits for general rooms
The NEC does not cap the number of receptacles on a residential 15 A or 20 A circuit, but electricians commonly put about 8 to 10 general receptacles on a 15 A circuit. The calculator suggests one circuit per 8 receptacles as a planning figure.
Before you wire
Local codes and inspectors have the final word, and permits are usually required. Electrical work carries risks of shock and fire; hire a licensed electrician when in doubt.