Electrical Voltage Drop Calculator
Vdrop = 2 × L × I × ρ ÷ cmil
- Voltage drop
- —
- % drop
- —
- NEC recommendation
- —
NEC recommends ≤ 3% for branch circuits and ≤ 5% combined feeder+branch.
About this tool
Electrical Voltage Drop Calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.
Category: Trade & Construction Calculators. Browse more Trade & Construction Calculators tools.