Voltage Drop Calculator

NEC-compliant. Single & three-phase. Instant results.

System Voltage

Phase

Load Current (Amps)

One-Way Distance (feet)

Wire Size (AWG)

Conductor Material

NEC Voltage Drop Guidelines

• Branch circuits: Max 3% voltage drop recommended (NEC 210.19 FPN)
• Feeder + branch total: Max 5% voltage drop recommended
• Note: These are NEC recommendations, not requirements — but inspectors and good practice follow them

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