Voltage Drop Calculator

Calculate voltage drop in electrical wires. Essential for ensuring proper wire gauge selection and NEC compliance.

Wire Information

Wire Gauge (AWG)12 AWG
Resistance per 1000ft1.588 Ω
Max Amps20 A

Voltage Drop

4.76 V (3.97%)

calculators.voltageDrop.status.marginal

End Voltage

115.24 V

Total Wire Length

200 ft

Visualization

Loss: 4.76VDelivered: 115.24V

NEC Guidelines

Excellent
≤ 2%
Branch Circuit
≤ 3%
Total System
≤ 5%
Excessive
> 5%

What is Voltage Drop?

Voltage drop is the decrease in electrical potential along a conductor carrying current. Some energy is lost as heat due to the wire's resistance.

Factors Affecting Voltage Drop

Wire length, gauge (thickness), material (copper vs aluminum), and current load all affect voltage drop. Longer runs and thinner wires increase drop.

Reducing Voltage Drop

To reduce voltage drop: use larger wire gauges, shorten wire runs, use copper instead of aluminum, or increase system voltage.