Circuit Breaker Calculator
Size a circuit breaker from load current with standard safety factors per NEC guidelines.
How to Use the Circuit Breaker Calculator
- Enter the total load current in amps.
- Set safety factor (1.25 for continuous loads).
- Enter circuit voltage.
- Get recommended standard breaker size.
Use Cases
- •Residential panel design
- •Commercial circuit sizing
- •Electrical load planning
Formula
Breaker ≥ Load × Safety Factor
Frequently Asked Questions
How accurate is this calculator?
Results are based on standard engineering formulas and are suitable for preliminary estimates.
What units are used?
SI units (metres, kg, kPa) are used unless otherwise noted.
Is it free?
Yes, all calculators are completely free.