Voltage Drop Calculator
Estimate voltage drop in a two-wire DC circuit from current, one-way length and conductor resistance.
How to Use the Voltage Drop Calculator
Enter circuit voltage, current, conductor length and resistance assumptions to estimate voltage lost along a DC circuit.
Practical Example
If a circuit has 10 A of current and total conductor resistance of 0.2 Ω, the voltage drop is 2 V.
Factors That Affect the Result
Wire material, gauge, temperature, one-way versus round-trip length, connection quality and AC reactance can change real voltage drop.
Frequently Asked Questions
What causes voltage drop?
Electrical resistance in conductors and connections.
Does wire length matter?
Yes.
Is this suitable for every AC circuit?
No. AC systems may require impedance and code-specific calculations.
What Affects Voltage Drop
Voltage drop increases with current, conductor resistance and circuit length. Conductor material, cross-sectional area and temperature affect resistance. For two-conductor DC circuits, account for the complete current path rather than only the one-way distance when the formula requires loop length.