Ten NEC-referenced calculators,
built for the jobsite.
Modern fields and pickers — no keystroke sequences to memorize, no manual required. For working electricians and apprentices.
iPhone · Voltage Drop and Ohm's Law free forever
Calculators
Every result shows its NEC article citation.
Voltage DropFree
Check a run, or find the wire size for a maximum drop.
Ohm's LawFree
Enter any two of V, I, R, P — get the other two.
Wire Size & Ampacity
60/75/90°C copper and aluminum, 240.4(D) breaker caps.
Conduit Fill
THHN in EMT, mixed sizes, instant compliant/overfilled verdict.
Box Fill
314.16(B) volumes with a per-item breakdown.
Motor FLA
Full-load current estimates for single- and three-phase motors.
Transformer Sizing
kVA and primary/secondary current sizing.
Dwelling Load
Service size by the 220.82 optional method.
Quick Reference
Common breaker and wire pairings at a glance.
Conversions
The unit conversions you actually use on a jobsite.
Built for pros
The features that turn a calculator into a professional document tool.
Inspector-ready PDF reports
Export any result with its inputs, NEC article citations, and your company name and license number. Hand it to the inspector.
Saved jobs
Group calculations by project, reopen them with every input restored, and export a whole job as one PDF packet for the submittal.
NEC 2017 · 2020 · 2023
Edition switching included. All editions, one price, forever — no paid "code year" upgrades.
Made for the field
Glove-friendly controls and a dark-mode default for panel rooms and attics.
Voltage Drop and Ohm's Law are free forever. One purchase unlocks the other eight calculators, PDF reports, saved jobs, and all NEC editions — on every device signed into your Apple ID.