Voltage Drop Calculator

Calculate voltage drop percentage for single-phase and three-phase circuits per IEC and NEC — free electrical design tool

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1φ2W: e = 2ρLI/A

1φ3W: e = ρLI/A

3φ3W: e = √3×ρLIcosφ/A

Input Parameters

Phase Type

1φ2W1φ3W3φ3W

Voltage (V)

Current (A)

Power Factor cosφ

Cable Length (m)

Conductor Size (mm²)

Conductor Material

Copper (ρ=1/58)Aluminum (ρ=1/35)

Results

Voltage Drop

3.69 V

Drop Percentage

1.85%

Load End Voltage

196.3 V

Pass/Fail Check

Branch Circuit (≤2%)

PASS

Feeder (≤3%)

PASS