How this calculator works
The National Electrical Code (NEC 210.52(A)) asks for wall outlets in living rooms, bedrooms and similar rooms so that no point along the floor line of any wall is more than 6 ft from one. Put another way, outlets are no more than 12 ft apart, and any wall space of 2 ft or more gets an outlet. Doorways and other openings that reach the floor split the walls into separate wall spaces, each counted on its own.
Worked example: a 14 × 12 ft room has 52 ft of wall. Two 3 ft doorways leave 46 ft of wall space. Counted wall by wall (doorways spread in proportion to the wall lengths) that is 6 outlets; if the wall space were one unbroken run, the absolute least would be 4. With no doorways at all the walls give 6. A large 24 × 16 ft room needs 8.
Assumptions and sources
- Under NEC 210.52(A), receptacles in the wall spaces of a living room, bedroom, dining room, den and similar rooms must be placed so that no point along the floor line of a wall is more than 6 ft from an outlet, which in practice means no more than 12 ft apart. A wall space is 2 ft or more of unbroken floor line; fixed room dividers and bar-type counters count. The result is a planning minimum: we spread the doorways over the walls in proportion to their length, so move them to where yours are and recount for an exact layout. Kitchens, bathrooms, hallways, garages and outdoor areas have their own rules, local codes add to the NEC, and more outlets than the minimum are almost always worth having. Have the work done or checked by a licensed electrician.
The formula and a worked example are shown above, so you can check any result by hand. Read how we calculate and check our numbers. Results are estimates for planning: supplier products vary, so check the size printed on the label.
Minimum wall outlets by room size (two 3 ft doorways)
The typical wall-by-wall count from this calculator.
| Room | Outlets (wall by wall) | Absolute minimum |
|---|---|---|
| 10 × 10 ft | 4 | 3 |
| 12 × 10 ft | 4 | 4 |
| 12 × 12 ft | 4 | 4 |
| 14 × 12 ft | 6 | 4 |
| 16 × 12 ft | 6 | 5 |
| 20 × 14 ft | 8 | 6 |
| 24 × 16 ft | 8 | 7 |
Tips before you buy
- The 12 ft rule is a maximum. Most electricians put an outlet on every wall space of a few feet or more, and add more where you will plug in a desk, TV or bedside lamps.
- Count wall space along the floor, not the ceiling. A doorway, a floor-length window or a wide archway ends one wall space and starts another.
- Many areas require tamper-resistant outlets in living areas, and arc-fault breaker protection on bedroom circuits. Check which edition of the NEC your area has adopted.
- Rooms behind a door count separately: a closet or a hallway follows its own rule.
Tools & materials for this project
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Frequently asked questions
How many outlets are required in a room?
One on every wall space of 2 ft or more, and never more than 12 ft apart, so no point on the wall is more than 6 ft from one. A 14 × 12 ft room with two doorways needs about 6.
What is the 12 foot rule for outlets?
The NEC wall-outlet rule: receptacles are placed so no point along a wall is more than 6 ft from one, which means they are no more than 12 ft apart.
How many outlets can be on one circuit?
The NEC does not set a number for a 15 or 20 amp household circuit: the limit is the circuit load. Use the circuit capacity calculator to check what a circuit can carry.
Does a doorway count as wall space?
No. A doorway breaks the wall: wall spaces on either side are counted separately, and a wall space is 2 ft or more of unbroken floor line.
Do these rules apply to kitchens and bathrooms?
No: kitchen counters, bathrooms, hallways, garages and outdoor areas have separate rules, and they usually require GFCI protection. This calculator is for living rooms, bedrooms, dens and similar rooms.
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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.