What Size Breaker for a Dryer?
A standard electric dryer requires a 30-amp, 240-volt double-pole breaker on 10 AWG copper wire with a NEMA 14-30 outlet.
Quick answer: dryer breaker, wire, and outlet
An electric clothes dryer runs on a dedicated 240-volt circuit protected by a 30-amp double-pole breaker. The circuit is wired with 10 AWG copper conductors (10/3 cable with ground) and terminates in a NEMA 14-30R receptacle. The table below summarizes the standard electric dryer circuit.
| Item | Specification |
|---|---|
| Breaker | 30-amp double-pole (two-pole), 240 V |
| Wire | 10 AWG copper, 10/3 cable with ground (two hots, neutral, ground) |
| Outlet | NEMA 14-30R (4-prong) for new installations |
| Circuit type | Dedicated 120/240 V branch circuit — no other loads |
The NEC math behind the 30-amp answer
A typical electric dryer heating element plus motor draws 5,000 to 5,600 watts. NEC 220.54 requires the dryer load to be calculated at 5,000 watts or the nameplate rating, whichever is larger. At 240 volts, a 5,600-watt dryer draws 5,600 W ÷ 240 V = 23.3 amps.
Because 23.3 amps exceeds a 20-amp breaker, the circuit steps up to the next standard breaker size listed in NEC 240.6(A): 30 amps. A 30-amp breaker pairs with 10 AWG copper, which has a 30-amp ampacity at the 60°C column of NEC Table 310.16 commonly applied to residential NM cable. The dryer uses both 240 V (heating element) and 120 V (motor, controls, drum light), which is why the circuit carries a neutral as well as two hot conductors.
3-prong vs 4-prong: what changed in 1996
Since the 1996 edition of the NEC, new dryer circuits must be 4-wire: two hots, a neutral, and a separate equipment ground, terminating in a NEMA 14-30 receptacle. Before 1996, 3-wire circuits with a NEMA 10-30 receptacle were permitted, with the neutral doubling as the equipment ground.
NEC 250.140 still allows an existing 3-wire NEMA 10-30 circuit to remain in service — you may fit a 3-prong cord to a new dryer and bond the dryer frame to the neutral per the manufacturer's instructions. What you may not do is install a new 3-wire dryer circuit: any new run must be 4-wire with an insulated neutral and a separate ground. The breaker size is 30 amps in both cases.
Gas dryers are different
A gas dryer heats with gas and only uses electricity for the motor, controls, and igniter, so it plugs into an ordinary 120-volt receptacle on a 15- or 20-amp circuit. A gas dryer does not need a 240-volt circuit, a double-pole breaker, or a NEMA 14-30 outlet. NEC 210.11(C)(2) does require a dedicated 20-amp laundry branch circuit for the laundry area receptacle(s), and a gas dryer typically plugs into that circuit.
Common dryer circuit mistakes
- Installing a 40-amp breaker on 10 AWG wire. The breaker protects the wire, not the appliance. A bigger breaker on the same wire removes overload protection and is a fire hazard — if a 30-amp breaker trips, find the fault; do not upsize the breaker.
- Running a new 3-wire circuit. The NEMA 10-30 allowance is for existing circuits only. All new dryer circuits must be 4-wire (NEC 250.140).
- Forgetting the bonding strap swap. When converting a dryer cord from 3-prong to 4-prong, the neutral-to-frame bonding strap inside the dryer terminal block must be removed; when fitting a 3-prong cord to an existing 10-30 circuit, it must be connected.
- Sizing aluminum like copper. If aluminum conductors are used, a 30-amp dryer circuit needs 8 AWG aluminum, not 10 AWG.
- Sharing the circuit. The dryer circuit is dedicated. Do not tap it for a freezer, receptacle, or second appliance.
Safety first
This page is educational reference material. A dryer circuit involves 240 volts on a two-pole breaker, panel work, and grounding/bonding decisions that must be done correctly. Fixed electrical installation work must be carried out by a licensed electrician in accordance with the applicable local wiring code (e.g. NEC/NFPA 70, BS 7671, AS/NZS 3000, IEC 60364), and many jurisdictions require a permit and inspection for a new dryer circuit.
Frequently asked questions
What size breaker do I need for an electric dryer?
A standard electric dryer needs a 30-amp, 240-volt double-pole breaker on 10 AWG copper wire with a NEMA 14-30 outlet. NEC 220.54 rates the dryer load at 5,000 watts or the nameplate rating, whichever is larger, and 5,000-5,600 W at 240 V lands the circuit at 30 amps.
Can I use a 40-amp breaker for a dryer?
No — not on the standard 10 AWG dryer circuit. The breaker protects the wiring, and 10 AWG copper is rated for 30 amps. A 40-amp breaker would allow the wire to overheat before tripping. If a correctly sized 30-amp breaker keeps tripping, have the dryer and circuit diagnosed instead of upsizing the breaker.
Can a dryer run on a 20-amp breaker?
No. An electric dryer draws roughly 23 amps at 240 volts, which overloads a 20-amp breaker. Only a 120-volt gas dryer belongs on a 15- or 20-amp circuit; electric dryers need a dedicated 30-amp, 240-volt circuit.
Is a dryer outlet 3-prong or 4-prong?
New dryer circuits must use the 4-prong NEMA 14-30 outlet, required since the 1996 NEC. The 3-prong NEMA 10-30 is a legacy configuration: NEC 250.140 permits existing 3-wire circuits to remain in service, but any new circuit must be 4-wire with a separate equipment ground.
What wire size do I need for a 30-amp dryer circuit?
10 AWG copper (typically 10/3 cable with ground, giving two hots, a neutral, and a ground). If aluminum conductors are used instead, the circuit requires 8 AWG aluminum for the same 30-amp rating.
Do gas dryers need a 240V outlet?
No. A gas dryer only uses electricity for its motor and controls, so it plugs into a standard 120-volt receptacle — normally the dedicated 20-amp laundry circuit required by NEC 210.11(C)(2). No double-pole breaker or NEMA 14-30 outlet is needed.
Related tools & references
- Breaker size calculator
- Wire size calculator
- Electrical load calculator
- Wire color codes reference
- Dryer wiring diagram
- 4-prong dryer outlet wiring diagram
Last verified: 2026-07-10