Voltage Drop for 12 AWG, 15 m, 15 A
Calculate the voltage drop on a 12 AWG, 15-meter circuit carrying 15 A — a standard household 15 A branch circuit.
How to use this tool
- Enter wire gauge (awg), one-way wire length and current in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your voltage drop and the full breakdown beneath it.
12 AWG wire is the standard for 20 A household circuits; see the voltage drop for a 15-meter run at 15 A load.
Frequently asked questions
- What is the maximum recommended voltage drop?
- The NEC recommends no more than 3% voltage drop on a branch circuit and no more than 5% combined (feeder + branch). Above 3% you may notice dimmer lights or reduced motor torque.
- Does the return conductor also contribute?
- Yes — current flows through both the hot and neutral (or ground-return) conductors, so the effective resistance is twice the one-way value.