⚡ Breaker Sizing Calculator

Estimate breaker size for a circuit. Always verify with a qualified electrician and local electrical codes. ⚠️ Educational only — not for actual electrical installations.
⚡ Circuit Parameters
Current drawn by the load
Wire current carrying capacity
Quick Examples:
📊 Standard Breaker Sizes (Typical)
10A
Lighting
16A
General Circuits
20A
Kitchen/Outlet
32A
Heavy Loads
40A
Ranges/Ovens
50A
EV Chargers
63A
Subpanels
100A
Main Service
⚠️ Critical Safety Information
Professional Required
Always hire a licensed electrician. DIY electrical work is dangerous and illegal in most areas.
Code Compliance
Follow NEC (US), IEC (International), or local electrical codes. Requirements vary by region.
Proper Sizing
Breaker protects wires, not appliances. Must not exceed conductor ampacity.
Warning
Incorrect breaker sizing can cause fires, equipment damage, or electrocution.
📚 Breaker Facts & Principles
Purpose
Circuit breakers protect wiring from overheating by interrupting current flow during overloads or short circuits.
125% Rule
For continuous loads (3+ hours), multiply load current by 1.25 before selecting breaker size.
Conductor Protection
Breaker size must never exceed the ampacity of the wire it protects (NEC 240.4).
Types
Standard, GFCI, AFCI, dual-function. Each has specific applications and requirements.