TradesHow this works
Voltage drop is what is left over after a long run eats into the voltage that reaches your load. When it is over your target, there is more than one way to fix it, and they are not equal. This tool takes your run and lays out the fixes that actually apply, with the resulting drop for each, so you can pick the one that fits the job instead of defaulting to a bigger wire every time.
Upsizing the conductor is the fix that always works, so it is the recommendation by default. But if the load can run at a higher voltage, or the run can take a shorter path, those are often cheaper. The tool shows all of them side by side.
Common questions
What are my options when a run drops too much voltage?
There are four common fixes. Upsize the conductor, which always works. Switch aluminum to copper, which lowers resistance at the same size. Raise the voltage, which cuts the percent drop sharply if the equipment supports it. Or shorten the run if a shorter path exists. This tool compares whichever apply to your situation.
Why does raising the voltage help so much?
For the same power, doubling the voltage halves the current, and the percent drop is measured against a bigger voltage. Between those two effects, going from 120 to 240 volts roughly quarters the percent drop. The catch is the equipment has to run at the higher voltage.
Is upsizing always the answer?
It always works, but it is not always the cheapest. If the load can run at a higher voltage, or a shorter route exists, those can be less material and less labor. The tool shows the tradeoffs so you can pick what fits the job.
Sources: NEC 210.19 voltage-drop informational note (2023) · NEC Chapter 9 Table 8 conductor properties (2023). Engine version 1.0.0. Risk tier 2.