Free NEC Code Practice Test
Load calculations, ampacity derating, box fill, and code comprehension — the math and code knowledge the journeyman exam tests.
Built for electricians and journeyman exam candidates
What's on the test?
Math & Algebra
5qFractions, percentages, ratios, and applied trade math
Number Sequences
3qFind the pattern and the next number
Reading Comprehension
4qShort passages with questions about the content
Mechanical Reasoning
4qFlow, gears, pulleys, levers, and physical principles
The journeyman electrician exam tests your knowledge of the National Electrical Code — not just rules, but the math behind them. Load calculations, ampacity derating, box fill, voltage drop, and code article comprehension all appear on the real exam. This free 16-question practice test covers all of it so you can see exactly where to focus your study time.
What is on the NEC practice test?
This practice test covers the core content of journeyman electrician exams: NEC code comprehension (reading and applying articles such as 110.3, 210.8, 210.12, and 250.4), load calculations using Ohm's Law and the power formula, ampacity derating for bundled conductors, box fill calculations using NEC Table 314.16(B), voltage drop as a percentage, and electrical concepts including series/parallel circuits and transformer turns ratios. The four sections — math, sequences, reading, and mechanical — mirror the format of trade aptitude and licensing exams.
What math does the NEC require?
The NEC embeds math throughout its articles. Electricians need to calculate load in amps using I = P ÷ V, apply the continuous-load rule (size conductors and breakers at 125% of the load, or limit the load to 80% of the rating), derate conductor ampacity when bundling — 80% for 4–6 conductors, 70% for 7–9, per NEC Table 310.15(C)(1) — calculate box fill by summing conductor volumes from Table 314.16(B), and check voltage drop using VD% = (VD ÷ Source Voltage) × 100. The NEC recommends keeping voltage drop at or below 3% for branch circuits and 5% total (feeder + branch).
How should you prepare for the journeyman exam?
Start by identifying which NEC articles your state exam emphasizes — most heavily test Article 210 (branch circuits), Article 230 (services), Article 240 (overcurrent protection), Article 250 (grounding and bonding), Article 300 (wiring methods), Article 310 (conductors), and Article 314 (boxes). Drill the most common calculations: load calcs, derating, and box fill. Practice reading NEC articles the way you would read a passage on a comprehension exam — answer only what the text says, not what you remember from the field. Take timed practice tests to build pace.
Frequently Asked Questions
Is this the official NEC exam?
No — this is a free practice test that covers the types of code knowledge and calculations that appear on journeyman electrician licensing exams. The real exam is administered by your state licensing board or a testing provider such as PSI or Prometric. Questions on the real exam vary by state, but the topics — NEC articles, load calcs, and code math — are representative.
What NEC articles are most tested on journeyman exams?
Most journeyman exams heavily test Article 210 (branch circuits, AFCI/GFCI), Article 240 (overcurrent protection), Article 250 (grounding and bonding), Article 300 (wiring methods), Article 310 (conductor ampacity and derating), and Article 314 (box fill). Service entrance (Article 230) and motors (Article 430) are also common. Your state may publish a reference list of tested articles.
Do I need an account to take this practice test?
No — start instantly, no account required. Enter your email at the end to receive your full results and a breakdown of which section to focus your study time on.