Voltage drop calculator
Calculate voltage drop using a supplied circuit coefficient, current and route length.
Every result has a reason.
Enter your values and calculate to see the result, formula and working here.
ΔV = coefficient × current × length ÷ 1,000Uses 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