Fuse & Breaker Sizing Calculator

Calculate the appropriate fuse or circuit breaker size for your electrical circuits. This helps ensure proper circuit protection and safety.

Enter the maximum current of your load
Select your system voltage
Select the type of load
Choose between fuse or circuit breaker
Enter the ambient temperature where the protection device will be installed

Standard Protection Device Sizes

Standard Size (A) Typical Applications Common Uses Notes
1-5 Low Power Electronics LED lighting, small devices Fast-acting fuses
5-15 General Purpose Small appliances, lighting Common household circuits
15-30 Medium Power Kitchen appliances, tools Standard branch circuits
30-60 High Power Air conditioners, heaters Dedicated circuits
60-100 Heavy Duty Electric vehicles, welders Specialized equipment
100+ Industrial Large machinery, distribution Professional installations

Important Considerations

  • Always use protection devices rated for your system voltage
  • Consider temperature derating factors
  • Account for inrush currents
  • Follow local electrical codes
  • Consider future expansion
  • Factor in installation conditions
  • Use appropriate mounting methods

Safety Tips

  • Never exceed device ratings
  • Use proper mounting hardware
  • Protect devices from physical damage
  • Label all protection devices
  • Use appropriate wire sizes
  • Follow proper grounding practices
  • Regularly inspect protection devices