About and contact

The Voltage Drop Calculator is a free reference tool for DC and single-phase wire sizing. It is funded by advertising and has no accounts.

What it is for

Checking voltage drop and the smallest wire for a run, with the assumptions shown. It is not a design service and not a code check.

Contact and reporting a wrong result

Email hello@voltagedropcalculator.app. If a result does not match the formula on the method page, include the inputs you used and the number you expected. The “Report a problem with this result” link under each result fills those in for you.

Operator

The operator name and address will be listed here before launch. (Owner decision.)