NEC Mastery

Developed with insights from licensed electricians and instructors nationwide, NEC Mastery has helped thousands pass their certification exams. Built around the 2023 NEC Code with 2024 updates.

Prepare for your NEC Certification Exam with the most comprehensive study tool designed for Journeyman, Master Electricians, Electrical Contractors, Maintenance and Sign Electricians, Inspectors, and Examiners.

NOW IN ENGLISH AND SPANISH
Every question, calculator, reference table and help article is available in both languages. Terminology follows NFPA 70, Código Eléctrico Nacional — the official Spanish edition of the NEC — so what you study matches the exam you sit. Texas TDLR offers Spanish-language electrician exams through PSI against the 2023 NEC, which is exactly the edition this app is written to. Pick your language on first launch or change it any time in Settings; the whole app switches instantly, read-aloud voice included.

Quick Reference
Your pocket electrician's reference with 13 categories and 100+ items — all offline:
• Electrical Formulas (Ohm's Law, AC/DC power, impedance, power factor)
• Ampacity Tables (NEC 310.16, temperature derating, conduit fill adjustment)
• Wire Properties & Insulation Types
• Conduit Fill (EMT, RMC, PVC) & Conduit Bending
• Box Fill Calculations
• Voltage Drop Tables & Max Distance Lookups
• NEMA Plug/Receptacle Configurations
• Motor FLC Tables & Branch Circuit Sizing
• Grounding (EGC & GEC Sizing, Electrode Types)
• Transformer Formulas & OCPD Sizing
• Electrical Symbols & Unit Conversions
Bookmark any reference, search by NEC article number or keyword, and jump directly to related calculators.

20 NEC Calculators
Professional-grade calculators with NEC code references:
Ohm's Law, Power Converter, Wire Size, Ampacity Derating, Voltage Drop, Conduit Fill, Box Fill, Breaker Sizing, EGC Size, GEC Size, Motor Circuit, Motor Feeder, Lighting Load, EV Charger Load, Residential Load, Commercial Load, Transformer OCPD, Transformer Conductor, Cover Depth, and Fault Current.

Electrician Hour Log
Track your apprentice or journeyman work hours:
• 12 work categories and 4 sector types
• Dashboard with charts and goal tracking
• PDF export for state board submissions
• iCloud sync across all your devices

Books & Tools
Curated recommendations from working electricians — code books, test instruments, hand tools, and study guides.

Exams Covered
- Master & Journeyman Electrician: F16, F17, G17, T17
- Residential Electrician: F18, G18, T18
- Maintenance & Sign Electricians: F19, F21, F22, F23
- Electrical Contractor: F49
- Inspectors & Examiners: E1, E2, E3

Why Choose NEC Mastery
- 8,000+ exam-style questions with answers, NEC references, and detailed explanations
- Fully bilingual — English and Spanish, switchable at any time
- 20 professional NEC calculators for on-the-job use
- Quick Reference with 100+ items — ampacity, formulas, NEMA configs, and more
- Electrician hour log with iCloud sync and PDF export
- Covers the