Voltage Drop Percentage Calculator
Calculate voltage drop percentage in electrical circuits based on wire size, length, current, and material. Understand how different factors affect voltage drop in your electrical installations.
Step 1: Circuit Parameters
Understanding Voltage Drop
Voltage drop occurs when electrical current flows through a conductor, causing a reduction in voltage. Excessive voltage drop can lead to equipment malfunction, reduced efficiency, and safety hazards.
Step 2: Material & Configuration
About Voltage Drop Limits
For branch circuits, the National Electrical Code (NEC) recommends a maximum voltage drop of 3% for branch circuits and 5% for feeder and branch circuits combined. Excessive voltage drop can cause equipment to operate inefficiently or fail.
Voltage Drop Calculation Results
Voltage Drop Percentage
Wire Size Comparison
| Wire Size (AWG) | Resistance (Ω/1000ft) | Voltage Drop | Drop Percentage | Compliance |
|---|
Voltage Drop Analysis
Voltage Drop Formula
VD = (2 × K × I × L) / CM for single phase
VD% = (VD / Voltage) × 100
Where: K = conductor resistivity, I = current (amps), L = one-way length (feet), CM = circular mil area of conductor. For three-phase systems, multiply by √3 instead of 2.
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