NEC · 210.11 / 220.14

How Many Outlets on a 15/20-Amp Circuit?

The question sounds simple, but the NEC answer depends entirely on whether you are wiring a dwelling or a commercial space — and for dwellings, the code's answer may surprise you.

NEC 2017 2020 2023 Last updated 2026-06-27

The dwelling exception: no fixed receptacle limit

For single-family and multifamily dwelling units, the NEC does not set a maximum number of receptacles per circuit. This is one of the most common misconceptions on the journeyman exam — many test-takers expect a fixed number like "eight outlets on a 15-amp circuit," but that figure appears nowhere in the code for dwellings.

Instead, the NEC handles dwelling load by using a general lighting load allowance expressed in volt-amperes per square foot of living space (Article 220, Table 220.12). That figure covers general lighting and general-use receptacles together. The assumption built into that calculation is that you will never have every outlet loaded at once, so counting individual receptacles is unnecessary for residential branch circuits. The practical implication is that an inspector cannot fail a dwelling rough-in simply because a 15-amp circuit has twelve or fifteen receptacles on it — the code does not prohibit that count.

What the code does require for dwellings is that certain circuits be present (small-appliance, laundry, bathroom) and that receptacles be placed so no point along a wall is more than a specified distance from an outlet (210.52). That spacing rule, not a receptacle count, is the binding dwelling requirement.

Non-dwellings: the 180 VA per outlet rule

For occupancies that are not dwelling units — offices, retail spaces, warehouses, and similar — the NEC takes a different approach. Section 220.14(I) assigns each general-use receptacle outlet a calculated load of 180 volt-amperes. That figure is used when determining the required feeder and service capacity; it is a load-calculation tool, not an explicit wiring limit, but it has a direct implication for how many receptacles a circuit can reasonably serve.

Worked example — 20-ampere circuit:

  • Circuit capacity: 20 A × 120 V = 2,400 VA
  • Load per receptacle (220.14(I)): 180 VA
  • Maximum count: 2,400 ÷ 180 = 13.3, rounded down to 13 receptacles

Worked example — 15-ampere circuit:

  • Circuit capacity: 15 A × 120 V = 1,800 VA
  • Load per receptacle (220.14(I)): 180 VA
  • Maximum count: 1,800 ÷ 180 = 10 receptacles

On the exam, if a question asks how many receptacles a non-dwelling circuit can serve and gives you the circuit amperage, 220.14(I) and the 180 VA figure are the tools to use.

Rule of thumb vs what the code says

A common field rule of thumb is "no more than 8 outlets on a 15-amp circuit" or "no more than 10 on a 20-amp." Those guidelines come from trade practice and some local interpretations of load diversity, not from the NEC itself. On the journeyman exam, you are being tested on the code, not the rule of thumb.

Occupancy NEC basis Receptacle limit?
Dwelling unit Article 220 (sq ft load allowance) No fixed limit in the code
Non-dwelling (general use) 220.14(I) — 180 VA per receptacle ~13 on 20 A; ~10 on 15 A (by calculation)

Knowing which rule applies to which occupancy type is the key to answering exam questions correctly. A question that names a house or apartment is asking about the dwelling rule. A question that names an office or store is asking about 220.14(I).

Continuous loads and effective circuit capacity

Even in cases where the NEC does not explicitly cap outlet count, the continuous load rule reduces the usable capacity of any circuit. If a load is expected to run for three hours or more, the branch-circuit conductors and overcurrent device must be rated at 125 percent of that load — or equivalently, the circuit should not be loaded above 80 percent of its rating for sustained use. A 20-ampere breaker in a commercial space serving continuously energized outlets is effectively limited to 16 amperes of continuous load, which changes the 180 VA math.

Lighting circuits in commercial buildings are a classic exam trap here: luminaires run continuously, so a 20-ampere circuit serving only lighting is limited to 80 percent of its capacity — 16 amperes of sustained load — before the 180 VA per-outlet calculation is even applied. Being able to layer the continuous load factor over the outlet-count calculation is the kind of multi-step reasoning journeyman exam questions are designed to test.

Practice questions on this rule

Real journeyman-exam practice questions from Loomi's bank — answer first, then reveal the explanation.

Q1 NEC 210.11(C)(3)

A dwelling has one bathroom, supplied by a single 20-ampere, 120-volt branch circuit. Which of the following is permitted on that circuit?

  1. A General lighting outlets in the adjacent bedroom
  2. B A countertop receptacle outlet in the kitchen
  3. C Receptacle outlets in a second bathroom down the hall
  4. D The bathroom's exhaust fan, per 210.23(B)(1) and (B)(2)
Show answer & explanation

Correct: D — The bathroom's exhaust fan, per 210.23(B)(1) and (B)(2)

Under 210.11(C)(3), when the 20-ampere circuit supplies a single bathroom, other equipment within that same bathroom — such as the exhaust fan — may be supplied by it per 210.23(B)(1) and (B)(2). Outlets in a second bathroom, the kitchen, or an adjacent bedroom fall outside 'the same bathroom' and are not covered by the exception.

Q2 NEC 210.11(C)(3)

A house has two bathrooms fed from one shared 20-ampere bathroom receptacle circuit. Per 210.11(C)(3), what else may this circuit supply?

  1. A The laundry room receptacle outlet
  2. B The exhaust fan in either bathroom, since both are bathrooms
  3. C A GFCI-protected garage receptacle
  4. D Nothing else — the single-bathroom exception does not apply when one circuit serves more than one bathroom
Show answer & explanation

Correct: D — Nothing else — the single-bathroom exception does not apply when one circuit serves more than one bathroom

The exception in 210.11(C)(3) only applies 'where the 20-ampere circuit supplies a single bathroom.' Once one circuit serves receptacles in more than one bathroom, that exception no longer applies, so the circuit must have no other outlets — ruling out fans in either bathroom, a garage receptacle, or the laundry receptacle.

Q3 NEC 210.52(D)

Which of the following mounting locations violates 210.52(D) for a bathroom sink receptacle?

  1. A 450 mm (18 in.) below the top of the countertop
  2. B On the side of the sink cabinet
  3. C On the wall adjacent to the sink
  4. D On the countertop next to the sink
Show answer & explanation

Correct: A — 450 mm (18 in.) below the top of the countertop

210.52(D) caps the receptacle at no more than 300 mm (12 in.) below the top of the sink or countertop, so 450 mm (18 in.) below is too low. The wall, countertop, and cabinet-side locations are all explicitly permitted.

Q4 NEC 210.52(D)

A bathroom has two sinks mounted in separate, widely spaced vanities. Per 210.52(D), what is the minimum number of receptacle outlets required?

  1. A One receptacle, but only if both sinks share a single countertop
  2. B Two receptacles — one within 3 ft of each sink's outside edge
  3. C One receptacle total for the bathroom, regardless of sink count
  4. D No receptacle is required unless the sinks are in a shared vanity
Show answer & explanation

Correct: B — Two receptacles — one within 3 ft of each sink's outside edge

210.52(D) requires a qualifying receptacle within 900 mm (3 ft) of each sink's outside edge, so each separate sink needs its own compliant receptacle — one bathroom-wide receptacle isn't enough when sinks are far apart.

All Branch Circuits practice questions (Article 210)

Frequently asked questions

Does the NEC limit how many receptacles you can put on a 15- or 20-amp circuit in a home?
No. For dwelling units, the NEC does not set a maximum receptacle count per circuit. The general lighting load for a dwelling is calculated by floor area (volt-amperes per square foot), not by counting individual receptacles. Exam questions about dwellings that ask for the NEC receptacle limit are looking for the answer: there is no fixed limit in the code.
Where does the 180 VA per receptacle figure come from?
Section 220.14(I) assigns a general-use receptacle outlet a load value of 180 volt-amperes for load-calculation purposes in occupancies other than dwellings. It is a load-calculation tool, not an explicit limit on how many receptacles a circuit can physically have.
What is the practical limit on receptacles for a commercial circuit?
Using the 180 VA figure from 220.14(I), a 20-ampere, 120-volt circuit has a total capacity of 2,400 VA, which works out to about 13 general-use receptacles. For a 15-ampere circuit the figure is about 10. These are load-calculation limits, not hard wiring limits, but they are the basis the exam uses for non-dwelling outlet counts.
Related articles
Branch Circuits (Article 210) Branch-circuit types, standard ratings, and required dwelling circuits. Continuous Load & the 125% Rule How continuous loads reduce the usable capacity of a circuit. Dwelling Load Calculator Calculate the general lighting and appliance load for a residence.
Loomi · NEC exam prep

Practice the NEC concepts in this article.

Loomi turns NEC content into 12,934 spaced-repetition exam questions built for the journeyman test. Try everything free for 3 days.

Get launch access