Voltage Drop Calculator

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Voltage Drop Calculator

Circuit Wire material Wire sizing Wire size Resistance (Ω/km) Voltage (V) Current (A) One-way length Max drop (%)

Advanced settings

Wire temp. (°C) Parallel runs / phase Power factor Reactance (Ω/km)

20°C conductor resistance is estimated from nominal area; AC reactance is zero unless entered. PF is lagging. Values are estimates, not NEC Table 9 data.

Result

Enter circuit details and calculate.

Voltage drop

Voltage drop (%)

Load voltage

Resistance / conductor

Power dissipated

Conductor area

Source vs. load voltage

Voltage along cable

Show calculation steps

Voltage-drop estimate only. Verify conductor ampacity, installation, protection and local electrical rules separately.

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