VDrop vs NEC Box & Conduit Calc

600V and less voltage drop calculator. Outputs provide the user details from the calculations to allow users to perform due diligence and develop confidence in the results. Custom voltages may be inputted (600V and less) also.

NEC Box & Conduit Calc is the fastest, most accurate way to calculate box fill, conduit fill, required conduit size, and wire volume — all to the NEC (National Electrical Code). Built for electricians, contractors, engineers, inspectors, and apprentices, it delivers instant, code-compliant results that save time on every job — right from your pocket, even offline. Key Features • Box Fill Calculator – Device counts, equipment grounding, internal clamps – All common box sizes and types – NEC-compliant volume with clear breakdowns • Conduit Fill Calculator – EMT, PVC, RMC, IMC & more – Multiple conductor sizes per conduit – NEC fill percentages with instant pass/fail • Required Conduit Size – Enter your conductors, get the correct conduit size instantly – See the next size up and down • NEC Reference Tables – Chapter 9 Tables 1, 4 & 5 at your fingertips – Browse every NEC box and conduit size • Accurate Wire Volume Data – Built-in AWG volume reference for field, shop, and inspection • Professional PDF Reports – Export clean, shareable reports for your records or the inspector • Clean, Simple Interface – Designed for electricians under time pressure – Easy to use with gloves – Works fully offline Perfect For • Electricians • Electrical contractors • Students & apprentices • Inspectors • Engineers & designers Download now and get code-compliant fill calculations in seconds — on every job.