Solve for any value — fill in two, get the third

Result

W = A × V  ·  A = W ÷ V  ·  V = W ÷ A

Estimate voltage drop and power loss over a cable run

Voltage drop

Voltage at load

Power lost in cable

NEC copper resistance values. Single-phase AC. Round-trip length used for calculation.

Enter load in amps for each circuit — assign to a phase

Circuit / load Amps Phase

Phase totals

0A

Phase A

0A

Phase B

0A

Phase C

A
B
C

Balance status

Total load

Max imbalance

Imbalance under 10% is generally acceptable. Over 20% risks overloading a single phase and tripping breakers. Neutral carries the imbalance current.