Voltage drop:
0.00Voltage Drop Calculator – Estimate Circuit Voltage Loss
Use this free voltage drop calculator to estimate voltage drop, percentage drop, and end voltage using NEC data, estimated wire resistance, or custom impedance values for your circuit.
Voltage Drop Calculator
Choose a method, enter your wire and load values, then calculate your voltage drop instantly.
Voltage Drop Calculator
Use NEC data, estimated resistance, or custom impedance values to estimate voltage drop for your circuit.
Result
Voltage drop percentage:
0.00%Voltage at the end:
0.00How to Use
- Select NEC data, Estimated resistance, or Other.
- Enter your voltage, wire data, distance, phase, and load current.
- Click Calculate to see the voltage drop and final voltage.
- Use the result to evaluate whether your circuit design is acceptable.
What This Calculator Does
This voltage drop calculator estimates electrical voltage loss across a conductor over a given distance. It can use NEC-style resistance values, estimated resistance with conduit and power factor adjustments, or a custom impedance input for more flexible calculations.
Frequently Asked Questions
What is voltage drop?
Voltage drop is the reduction in voltage that occurs as electrical current flows through a wire due to resistance or impedance.
Why does voltage drop matter?
Excessive voltage drop can reduce equipment performance, cause overheating, and make a circuit less efficient.
What is the difference between the three modes?
NEC data uses preset wire resistance values, Estimated resistance adjusts values based on more assumptions, and Other lets you enter your own impedance or resistance directly.