Provider: 509 Electric LLC
TrueFill is a conduit-fill calculator for electrical professionals. Enter your conductors and raceway and TrueFill returns the smallest passing trade size, fill percentage against the allowable fill rule, remaining area, and the supporting math — with every input, assumption, and source reference shown so you can check the work.
How to use: Pick a raceway type, add your phase, neutral, ground, and spare conductors with their sizes and insulation, and tap Calculate. TrueFill shows the recommended conduit, the fill headroom, and a full math trace. Save a draft to revisit the exact revision later, and open Show Math to see the conductor-area breakdown and references.
This version uses demo code data only. Results are clearly labeled as a demo/estimating aid and are blocked from final, export-ready, BOM, pricing, and bid-total use. All calculations are performed locally on your device; nothing is sent to a server.
Results are a calculation aid for qualified electrical professionals. Always verify conductor counts, fill percentages, derating, terminal temperature ratings, equipment-ground sizing, jurisdiction requirements, and project specifications against the NEC and applicable project documents before pulling wire. TrueFill is not a substitute for a licensed engineer or a code compliance determination.
Need help or found a bug? Email nick@509electric.com with the app version, device model, iOS version, and a short description of what you were doing.