Voltage Drop & Cable SizingEngineering

Electrical Wire Voltage Drop & Copper Cable Sizing Calculator

Calculate electrical voltage drop (ΔV in Volts & %), copper conductor resistance (Ohms), and power dissipation (Watts) to size cables compliant with NEC and IEC standards.

Calculator Inputs

Live Real-Time
V
Quick select:
A
Quick select:
m
Quick select:
Calculated ResultVoltage Drop & Cable Sizing

Voltage Drop Percentage (%)

3.41%%

Voltage Drop (ΔV in Volts)

7.84 V

Delivered Voltage at Load (V)

222.16 V

Cable Power Loss (Watts)

125.44 W

Conductor Loop Resistance

0.49 Ω

Voltage Delivery Profile

Load Voltage (V)
222.16 V(97%)
Drop (V)
7.84 V(3%)

Detailed Calculation Breakdown

Drop (V)
7.84 V
Load Voltage (V)
222.16 V
Loss (W)
125.44 W

Calculation Methodology

Copper Loop Resistance: R = 2 * (ρ * L) / A, where ρ = 0.0175 Ω·mm²/m. Voltage Drop: ΔV = I * R. Percentage Drop = (ΔV / V_supply) * 100. Power Loss: P = I^2 * R.

Important Legal & Educational Disclaimer

This electrical engineering tool computes single-phase AC/DC conductor voltage drops.

This calculator is designed for educational and informational purposes only based on public statutory frameworks. The outputs do not constitute binding financial, tax, or legal advice. We assume no liability for decisions made based on these estimations. Always verify with the relevant official authorities or a certified professional advisor.

Frequently Asked Questions

NEC recommends a maximum 3% voltage drop across branch circuits and 5% maximum total drop from service panel to terminal loads.
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