ReferenceNEC 2023 Table 240.6(A) · Updated

Standard breaker sizes

The standard breaker and fuse sizes in NEC Table 240.6(A) are 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000, 5000 and 6000 amps. That is 38 ratings. A breaker on this list is not automatically allowed on a given wire; the wire still has to be large enough for it.
Smallest10A
Largest6,000A
Ratings38
SourceNEC 240.6(A)

Standard breaker size chart

NEC 2023 Table 240.6(A): standard ampere ratings for fuses and inverse time circuit breakers. Highlighted sizes link to the wire size for that breaker.
1015202530
3540455060
708090100110
125150175200225
250300350400450
5006007008001000
12001600200025003000
400050006000

Fuses have 4 more standard ratings: 1, 3, 6 and 601 amps. Breakers and fuses with other ratings are permitted; they are just not “standard” for the rules that refer to this list. A given panel accepts only the breakers its label lists. Source: NEC 2023 Table 240.6(A), checked against NFPA’s printing of the table on November 14, 2026.

Continuous load each size can carry

A load that runs for three hours or more is a continuous load. The breaker must be rated at least 125% of it (NEC 210.20(A) for branch circuits, 215.3 for feeders), which is the same as loading a standard breaker to no more than 80% of its rating. Breakers listed for 100% operation are the exception.

Largest continuous load, in amps, on each standard breaker up to 200A (80% of the rating).
BreakerContinuousBreakerContinuous
10A8A70A56A
15A12A80A64A
20A16A90A72A
25A20A100A80A
30A24A110A88A
35A28A125A100A
40A32A150A120A
45A36A175A140A
50A40A200A160A
60A48A

When you may use the next size up

Wire ampacities do not always land on a standard breaker size. NEC 240.4(B) lets you use the next standard size above the wire’s ampacity when all three of these are true: the ampacity does not match a standard rating, the next standard rating is 800A or less, and the circuit is not a branch circuit feeding more than one receptacle for cord-and-plug portable loads. The load itself must still be no more than the wire’s ampacity.

Copper conductors at 75°C (NEC Table 310.16) and the largest standard breaker for each when the 240.4(B) conditions are met.
Copper wireAmpacityBreakerHow
850A50AExact match
665A70ANext size up
485A90ANext size up
3100A100AExact match
2115A125ANext size up
1130A150ANext size up
1/0150A150AExact match
2/0175A175AExact match
3/0200A200AExact match
4/0230A250ANext size up

Sizes are AWG. 14, 12 and 10 AWG copper are not in this table because NEC 240.4(D) limits their breakers to 15A, 20A and 30A. On circuits of 100A or less, use the 60°C ampacity unless the wire and every terminal are rated 75°C (110.14(C)); see the ampacity chart.

MCA and MOCP on an equipment nameplate

Air conditioners, heat pumps and similar equipment print two numbers on the nameplate. Minimum circuit ampacity (MCA) is the smallest wire ampacity allowed. Maximum overcurrent protection (MOCP, or MOP) is the largest breaker or fuse allowed. Size the wire from MCA and pick a standard breaker no larger than MOCP; do not round MOCP up to the next standard size. For an example, see the mini-split circuit guide.

Where to go next

If you know the breaker and need the wire, use the breaker wire size chart. If you are feeding a second panel, the sub panel wire size chart covers 30A to 200A by run length. The rules behind this page are in NEC Article 240: overcurrent protection.

Frequently asked questions

What are the standard breaker sizes?

NEC Table 240.6(A) lists 38 standard ratings: 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500, 600, 700, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000, 5000 and 6000 amps.

What are the standard breaker sizes for a house panel?

The standard ratings up to 200A are 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175 and 200 amps (NEC 240.6(A)). Which of them fit your panel depends on the breakers its label lists.

Is 10A a standard breaker size?

Yes. 10A is the smallest standard rating in the NEC 2023 table; earlier editions started at 15A.

What are the standard breaker sizes over 3000 amps?

4000, 5000 and 6000 amps. 6000A is the largest standard rating in NEC 240.6(A).

Is there a 55 amp breaker?

55, 65 and 75 amps are not standard ratings in NEC 240.6(A). The standard sizes around them are 50A and 60A, 60A and 70A, and 70A and 80A. Nonstandard ratings are permitted, but most panels only list the standard ones.

Can I always go up to the next breaker size?

No. NEC 240.4(B) allows the next standard size above the wire’s ampacity only when the ampacity does not match a standard rating, the next size is 800A or less, and the circuit is not a multi-receptacle branch circuit for cord-and-plug loads. It never applies to 14, 12 or 10 AWG copper, which 240.4(D) holds to 15A, 20A and 30A.

Requirements vary by state. NEC edition, licensing, permits, and GFCI rules differ by jurisdiction. Check your state or pick it below for personalized info across WireRef.
Important: For reference only. Not a substitute for a licensed electrician. Electrical work can cause serious injury, death, fire, or property damage if performed incorrectly. Always hire a licensed electrician for electrical work, especially for service upgrades, panel work, and 240V circuits. Values are derived from NFPA 70 (NEC) for educational purposes. Always verify against your locally adopted NEC edition and amendments - local jurisdictions may enforce stricter requirements. WireRef provides reference information only and is not responsible for work performed based on this content. NEC® is a registered trademark of the National Fire Protection Association. Free NEC access via NFPA · OSHA Electrical Safety · Terms of use.

NEC 2023 references verified February 2026