Skip to main content

learn.howToCalculate

learn.whatIsHeading

Circuit Breaker Size Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.

Fórmula

Breaker Size = Load Watts / Voltage × 1.25 (125% NEC rule)

Guia passo a passo

  1. 1Calculate total load in watts, divide by voltage, multiply by 1.25
  2. 2Apply the formula using your project measurements
  3. 3Add required safety factors or waste allowances per code

Exemplos resolvidos

Entrada
2400W load, 120V circuit
Resultado
Breaker = 2400/120 × 1.25 = 25A → use 30A breaker

Erros comuns a evitar

  • Not applying code-required safety factors or derating
  • Forgetting to account for waste and cut losses in material estimates

Pronto para calcular? Experimente a calculadora Circuit Breaker Sizing gratuita

Experimente você mesmo →

Configurações

PrivacidadeTermosSobre© 2026 PrimeCalcPro