Voltage Drop Calculator
Calculate voltage drop, power loss, and wire sizing for electrical circuits with NEC compliance checking
Circuit Parameters
Enter your electrical circuit specifications
Current flowing through the circuit
Distance from panel to load (one way)
System voltage level
Wire gauge (American Wire Gauge)
Number of parallel conductors per phase
Operating temperature (affects resistance)
Voltage Drop Analysis
Calculated voltage drop and system performance
voltageDrop.enterCircuitParameters
Common Circuit Types
Click on a scenario to quickly set typical electrical circuit parameters
voltageDrop.residentialCircuit15A
Current: 15A
Distance: 50ft
Voltage: 120V
Wire: 14 AWG copper
voltageDrop.residentialCircuit20A
Current: 20A
Distance: 75ft
Voltage: 120V
Wire: 12 AWG copper
voltageDrop.evCharger
Current: 32A
Distance: 100ft
Voltage: 240V
Wire: 10 AWG copper
Industrial Motor Feed
Current: 50A
Distance: 200ft
Voltage: 480V
Wire: 6 AWG copper
Voltage Drop Guidelines
NEC Recommendations
- • voltageDrop.branchCircuitsMax
- • voltageDrop.feedersMax
- • voltageDrop.combinedSystemMax
- • voltageDrop.criticalCircuitsLower
- • voltageDrop.motorStartingSpecial
Effects of Voltage Drop
- • Reduced equipment performance and efficiency
- • Overheating of motors and other equipment
- • Increased energy consumption and costs
- • Shortened equipment lifespan
- • Potential starting problems for motors