Voltage Drop Calculator

Determine voltage losses over wire feeder runs

Parameters

Material
Phase
Load Current15 A
Max 20A (safety limit)
One-Way Distance100 Feet

Voltage Drop

5.93 V

(4.94%)

Warning (3% - 5%)

Terminal Voltage

114.07 V AC

Effective voltage supplied to the terminal load.

Conductor Properties

copper conductor

AWG size area is 6,530 circular mils.

Recommended Overcurrent Size

19 Amp Breaker

Calculated at 125% code buffer margin.

NEC Voltage Drop Recommendations

The **National Electrical Code (NEC)** recommends that the maximum voltage drop on a branch circuit should not exceed **3%** of the nominal source voltage. The total combined drop of both the feeder and the branch circuit should not exceed **5%** for maximum operating efficiency.

If your voltage drop exceeds these recommendations (yielding a Warning or Fail status), you should **upsize the wire conductor (decrease the AWG size)**, use copper instead of aluminum, or reduce the circuit run distance.