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Cables & circuits

Voltage drop calculator

Calculate voltage drop using a supplied circuit coefficient, current and route length.

Your values

Example values are prefilled. Replace them with your own.

mV/A/m

Enter the full circuit coefficient appropriate to your cable, supply arrangement, temperature and power factor. It must already include the return path or three-phase factor.

A
m
V

Result

Voltage drop
Ready

– – –

Enter your values and press Calculate result.
FormulaΔV = coefficient × current × length ÷ 1,000

Within this model

Uses your supplied full-circuit mV/A/m coefficient. Length is the one-way route length; no extra return-path or √3 multiplier is applied. The coefficient must match the circuit and operating conditions. This calculation does not select a cable or assess a voltage-drop limit.

What the numbers mean

Multiplying millivolts per ampere per metre by current and route length gives millivolts. Division by 1,000 converts to volts. Use the coefficient from the relevant cable data for your circuit; a bare conductor resistance is not interchangeable with a full-circuit coefficient.

Formula reference: Eland Cables · Voltage drop ↗

A worked example

With a supplied coefficient of 4 mV/A/m, 10 A over 25 m gives 1 V drop. Relative to 230 V, that is approximately 0.43478261%.

Validation, precision and limitations

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