Electrical Calculators

Calculators

• Breaker Size Calculator
  Estimate minimum circuit ampacity and breaker requirement from continuous and noncontinuous load currents using editable multipliers.
• Electrical Load Calculator
  Estimate total electrical demand, apparent power and current from connected load, demand factor, voltage, phase factor and power factor.
• Generator Sizing Calculator
  Estimate generator running and starting capacity from total running watts, the largest additional surge load and an editable reserve margin.
• Voltage Drop Calculator
  Estimate conductor voltage drop and percentage voltage drop from current, one-way length, conductor resistance and circuit voltage.
• Wire Size Calculator
  Estimate the minimum conductor circular-mil area from current, distance, allowable voltage drop and conductor resistivity.

Guides

• Breaker Size Guide: How to Size Circuit Breakers for Any Load
• Electrical Load Calculator: How to Estimate Home Panel and Circuit Loads
• Generator Sizing Guide: How Many Watts Do You Actually Need?
• Voltage Drop Explained: NEC Limits, Wire Sizing & Worked Examples
• Wire Size Calculator: How to Choose the Right AWG for Any Circuit

Frequently Asked Questions

What does the Electrical Load Calculator calculate?

Estimate total electrical demand, apparent power and current from connected load, demand factor, voltage, phase factor and power factor.

Are the results guaranteed or code-compliant?

No. It is a preliminary educational estimate and does not establish code compliance, equipment suitability, permit approval or installation safety.

Can I change the assumptions?

Yes. The calculator exposes the main design, operating or financial assumptions so you can replace examples with project-specific values.

Should the result be independently verified?

Yes. Verify the result with applicable codes, manufacturer data, approved load calculations and a qualified electrician, engineer or HVAC professional.