Fieldwatt Electrician NEC Calc

Five NEC calculators that work with no signal. Fieldwatt is a field calculator suite for electricians, apprentices, and inspectors. Every calculation runs on the phone — no account, no network, no waiting. Open it in a crawlspace, a mechanical room, or a job trailer with one bar and it still answers instantly. WHAT'S INSIDE • Voltage Drop — 1-phase and 3-phase, copper or aluminum, checked against the 3% branch / 5% total recommendation. When a run fails, it names the size that passes. • Wire Ampacity — minimum conductor from NEC Table 310.16, with the 125% continuous-load multiplier applied where it belongs. • Conduit Fill — minimum EMT, PVC-40, or RMC for your conductor count, per Chapter 9 Tables 1, 4, and 5. • Box Fill — total volume required per NEC 314.16, counting conductors, devices, clamps, and grounds the way the article does. • Conduit Bending — offset multipliers, mark spacing, shrink, and 90° stub take-up. IT TELLS YOU THE RULE, NOT JUST THE NUMBER Most calculators hand back a figure and leave you to defend it. Fieldwatt hands back the figure and the article behind it: • Choose the 90°C column and it warns you that 90°C is a derating column. Per NEC 110.14(C) terminations are listed for 60°C or 75°C, and sizing off 90°C is how a conductor passes arithmetic and fails inspection. • Mark a load continuous and it sizes at 125% up front, instead of reporting a code requirement as an afterthought. • Upsize for voltage drop and it reminds you that NEC 250.122(B) makes you upsize the equipment grounding conductor in the same proportion. Every result carries its citation — 310.16, 314.16, 250.122(B), Chapter 9 Tables 1/4/5 — so you can check the work against the book. BUILT FOR THE JOBSITE • Fully offline. The whole app ships on the device. • No account required to calculate. • No ads. • Large type and big touch targets, for gloves and bad light. • Dark by default, because most of this work happens in the dark. FREE All five calculators are free. Signing in is optional and only adds saved jobs and material lists for accounts that already have them. NEC 2023. For guidance only — verify against the code edition your AHJ enforces and any local amendments.