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.

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iPhone · Wire Size, Voltage Drop and saved jobs free forever

Calculators

Every result shows its NEC article citation.

Wire Size & AmpacityFree

60/75/90°C copper and aluminum, 240.4(D) breaker caps.

Voltage DropFree

Check a run, or find the wire size for a maximum drop.

Conduit Fill

THHN in EMT, mixed sizes, instant compliant/overfilled verdict.

Box Fill

314.16(B) volumes with a per-item breakdown.

Dwelling Load

Service size by the 220.82 optional method.

Motor FLA

Full-load current estimates for single- and three-phase motors.

Transformer Sizing

kVA and primary/secondary current sizing.

Ohm's Law

Enter any two of V, I, R, P — get the other two.

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.

PDF job packets

Export a whole job as one document for the submittal. Saving calcs to a job and reopening them with every input restored is free.

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.

$19.99 one time

Wire Size, Voltage Drop and saved jobs are free forever. One purchase unlocks the other eight calculators, PDF reports, and all NEC editions — on every device signed into your Apple ID.