Voltage Drop Calculator
Calculate voltage drop across a cable run from length, current and conductor size.
Assumptions used in this calculation
- Round-trip length: Assumes a single-phase circuit where current flows out and back, doubling the effective conductor length.
About this calculator
The voltage drop calculator estimates the voltage lost over a cable run based on its length, current, cross-sectional area and conductor material, and shows the drop as a percentage of supply voltage.
Worked example
50m copper run at 10A, 2.5mm²
Result: 7V drop (3.04%)
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