Calculate electrical voltage drop for wire runs. Determine the right wire gauge to minimize voltage drop and power loss in your electrical circuits.
Voltage Drop
5.94 V
4.95%
Voltage drop exceeds 3%. Consider larger wire for efficiency. Consider using 1 AWG wire.
Phase
Conductor Material
Voltage Drop
4.95%
5.94 V
End Voltage
114.06 V
At load end
Wire Resistance
0.3960 Ω
Total round trip
Power Loss
89.10 W
Heat dissipation
| Wire Gauge | Voltage Drop | Drop % | Status |
|---|---|---|---|
| 14 AWG | 9.42 V | 7.85% | High |
| 12 AWG | 5.94 V | 4.95% | High |
| 10 AWG | 3.72 V | 3.10% | High |
| 8 AWG | 2.33 V | 1.94% | OK |
| 6 AWG | 1.47 V | 1.23% | OK |
| 4 AWG | 0.92 V | 0.77% | OK |
Single Phase:
Vd = 2 × I × R × L / 1000
Where R is resistance per 1000 ft
Three Phase:
Vd = √3 × I × R × L / 1000
√3 ≈ 1.732
Voltage drop is the reduction in voltage as electrical current flows through a conductor. It occurs because all conductors have some resistance. Excessive voltage drop can cause equipment to malfunction, motors to overheat, and lights to dim.
The NEC (National Electrical Code) recommends no more than 3% voltage drop for branch circuits and 5% total (feeder + branch). For sensitive electronics, aim for 2% or less. Higher drops waste energy and can damage equipment.
Use larger wire gauge (smaller AWG number = larger wire), shorten the wire run, reduce the load current, use copper instead of aluminum, or increase the supply voltage. Larger wire is usually the most practical solution.
Aluminum has about 61% the conductivity of copper, so it requires larger gauges for the same current capacity. Aluminum is cheaper and lighter but needs more care during installation due to oxidation and thermal expansion differences.
Determine your voltage, current, and distance. Calculate voltage drop for different wire sizes until you find one with acceptable drop (typically ≤3%). Also verify the wire's ampacity rating meets your current requirements.
Single phase uses two conductors (hot and neutral). Three phase uses three hot conductors with 120° offset. Three phase is more efficient for larger loads and motors, with less voltage drop for the same power delivery.
Voltage Drop
5.94 V
4.95%