Breaker Sizing

Formula and source

OCP = 125% × continuous load + 100% × non-continuous load (NEC 210.19(A) / 215.2(A)(1) / 215.3); next-standard-size rule per NEC 240.4(B); standard sizes per NEC 240.6(A).

NEC 2023 (NFPA 70).

Audience

This tile is built for electricians and the adjacent professions in the Electrical group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.

Related tools

• Wire Ampacity
• Motor Full Load Amps
• Service Load Calculation (Residential)

Posture

Rough Logic answers the math question the working professional asks on the job. The site is a calm, fast, ad-free, account-free, ever-free reference. It does not interpret code. It does not replace the licensed professional. It does not store your inputs. The Authority Having Jurisdiction governs all installations and inspections.