Voltage drop calculator

Single phase AC

Three phase AC

DC

Resistor

Single phase AC voltage drop calculator

Supply voltage

Current

Cable length

Cable conductor cross-sectional area

Material resistivity

Three phase AC voltage drop calculator

Supply voltage

Current

Cable length

Cable conductor cross-sectional area

Material resistivity

DC voltage drop calculator

Supply voltage

Current

Cable length

Cable conductor cross-sectional area

Material resistivity

Resistor voltage drop calculator

Resistance

Mode

Enter current Enter voltage

Current

About us

Welcome to the Voltage Drop Calculator. We provide engineers and hobbyists with a free, accurate tool to calculate voltage drop, power loss, and conductor resistance.

Privacy policy

We do not collect personal data. All calculations run 100% client-side in your browser.

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Theory

Here you can explain the underlying equations, e.g. Ohm’s law ΔV = I·R, single-phase vs three-phase formula, etc.

Single-phase: ΔV = I·ρ·L/A
Three-phase: ΔV = √3·I·ρ·L/A
DC: ΔV = I·ρ·L/A