California Electrician PrepCertification, exam and code, in one place

Checked against primary sources 2026-09-05

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California Electrician Exam Tools: Calculators and Labs

Twenty four tools, and every one of them shows the working rather than only the answer, because the working is the part that transfers to the paper. They hold the 2026 table values, and where a section number differs in the 2023 book California tests on, this page names it.

Test yourself: thirty free questions, timed

On this page
  1. The eight calculators
  2. The six games
  3. The four labs
  4. The five drills
  5. The hours calculator
  6. Which edition these tools hold
  7. The tools that name a number which differs
  8. How to use them without learning the wrong thing
  9. Questions people ask
  10. What this page cites

The eight calculators

Voltage drop calculator. Chapter 9 Table 8 conductor properties built in, with volts dropped, percent, volts at the load, the K factor method and a sizing mode.

Conduit fill calculator. Pick the raceway, add the conductors, read the fill percent and the trade size that fits, with Chapter 9 Table 4 and Table 5 values held in the page.

Box fill calculator. Every box in Table 314.16(A) and the 314.16(B) allowances, counting what enters the box step by step rather than handing you a total to trust.

Wire size calculator. Load current in, conductor size out, on Table 310.16, with the 240.6(A) device and the Table 250.122 equipment grounding conductor beside it.

Ampacity calculator. Table 310.16 with the ambient correction and the adjustment for bundled conductors applied in order, then the termination cap, so you can see which step decided the answer.

Motor calculator. Full load current from Tables 430.248 and 430.250, then the 430.22 conductor, the 430.32 overload and the 430.52 device.

Transformer calculator. kVA in, primary and secondary amps out, with the maximum device and the secondary conductor.

Ohm's law calculator. Type any two of volts, amps, ohms and watts and read the other two with the formula named, plus three phase and power factor.

The six games

Ampacity sprint. A timed Table 310.16 game, ten prompts a round in copper, aluminum or a mixed level with the 240.4(D) cap.

Wire size sprint. The same table in reverse. Ten loads a round, pick the smallest conductor that carries each.

Code navigation race. Twenty prompts a round against the clock: pick the chapter, the article or the section out of four.

Definitions flashcards. Sixty Article 100 terms, tap to flip, missed cards come back, plus a timed twenty card sprint.

Which table. Read the job, name the table or section you'd open. Forty four of them across three levels.

The calculation ladder. Eight rungs of exam arithmetic in the order they get harder, box fill through tap rules, ten problems each with the working shown. The first rung is free and the rest open with the $79 bank.

The four labs

A lab is a page you work rather than read. You drag something, turn something or connect something, and it answers with the number it just changed and the section that governs it. All four run in the browser with no account.

Conduit bending simulator. Drag the rise and turn the angle dial, and the multiplier, the shrink, the take up and every mark move with it.

Switch wiring lab. Drag conductor ends onto terminals on a three way and four way, flip the switches, and a checker names the section behind each fault.

Box fill lab. Drop conductors, grounds, a device yoke, clamps and fittings into a drawn box and watch the fill rise by the allowance each one draws.

Grounding electrode lab. Put electrodes in the ground, bond them into one system, and size the grounding electrode conductor from Table 250.66 and its ceilings.

The hub at all four labs lists them together.

The five drills

The diagnostic. Twenty four questions across eight content areas. It scores every area, orders them worst first and names your two weakest, which is the right thing to do before you plan a single week of study.

The article drill. A timed drill on which article governs a question, scored in seconds, because the code half of an exam is lost on search time rather than on knowledge.

Spot the violation. Twelve drawn scenes, click the one thing that's wrong, with an explanation on every region including the ones that are fine.

Grounding or bonding. The most confused pair in the trade, sorted one item at a time. Grounding reaches earth, bonding ties metal together, and several things do both.

The daily question. One original question a day, the same one for everybody, with the worked explanation, the section cited and a streak counter.

The hours calculator

Hours to exam answers the licensing question rather than the code question: given the hours you already have, when can you sit?

It's built on California's own rule. The General Electrician certification takes 8,000 hours worked for a C-10 electrical contractor under CCR Title 8 section 291.1, spread across two or more work areas with a ceiling on each, and someone short of the hours or the instruction can register as an electrician trainee in the meantime.

It's free, it needs no account, and nothing leaves your browser unless you email the result to yourself.

Which edition these tools hold

The table values in these calculators were read out of the 2026 National Electrical Code. California's certification exam supplies the 2023 edition on screen and the 2025 California Electrical Code is built on the 2023 model code, so here's exactly what that does and doesn't mean.

The table numbers are the same in both books. Table 310.16 for ampacity, 314.16 for box fill, Table 250.66 for the grounding electrode conductor, the Article 430 motor tables, and Chapter 9 Tables 1, 4, 5 and 8 for raceway fill and conductor properties. We read all of those at those numbers in the 2026 text, and our record of what moved has no entry for Article 310, Article 314 or Chapter 9.

On the values inside the tables we're more careful. We read the 2026 tables and we haven't set them against a 2023 printing row by row. Use the tools to learn the method and check any number that decides an answer in the book the exam puts in front of you.

One subsection is worth watching. The per conductor volume allowance table inside 314.16 is a case our crosswalk records as unresolved between editions, so read the subsection heading in your own copy rather than carrying a letter across.

The tools that name a number which differs

Eleven of the twenty four name at least one section that carries a different number in the 2023 book California tests on. Here they are, with both numbers.

The other thirteen, including six of the eight calculators and all four labs, cite sections that read the same in both editions. Which edition has the full list.

How to use them without learning the wrong thing

A calculator that hands you an answer teaches you nothing you can carry into an exam. That's why every tool here shows the steps.

Work the problem on paper first, then run it through the tool and compare the steps rather than the totals. A wrong total tells you something broke. A step by step comparison tells you which step.

Then log the step you got wrong. Twenty problems logged that way point at your two real weak spots inside a week, which is faster than any score can.

Questions people ask

Are these California electrician exam tools free?

All of them except the paid rungs of the calculation ladder, which shares the $79 practice bank. Nothing needs an account, and nothing you type leaves your browser unless you email a result to yourself.

Can I use a calculator on the California electrician exam?

The Candidate Information Bulletin doesn't list what the workstation provides, so ask CPS HR at ecuexams@cpshr.us before your date. On the separate CSLB contractor exams, calculators are named as a prohibited item.

Which NEC edition do these calculators use?

The table values were read out of the 2026 edition. The table numbers are the same in both books, and where a section number differs the tool page prints both. Check any value that decides an answer against the book the exam supplies.

Which tools name a number that differs in the 2023 book?

Eleven of the twenty four. The transformer calculator cites 450.5 in the 2026 book, which is 450.3 in the 2023 edition, and the Ohm's law calculator points at Article 120, which is Article 220 in the 2023 edition. This page lists the rest.

What is the ampacity sprint?

A timed drill on Table 310.16. You're given a conductor and a temperature column and you name the ampacity against a clock. The wire size sprint runs the same table in reverse.

Is there a California electrician hours calculator?

Yes, at hours to exam on this site. It takes the hours you have and gives you the date you can sit, against California's 8,000 hours for the General Electrician certification under CCR Title 8 section 291.1.

What is a lab?

A page you work rather than read. You drag conductors into a box or bend a piece of conduit on screen, and the page answers with the number it just changed and the section that governs it.

Put it to the test

Thirty free questions, timed, with the working shown

Every miss comes back with the arithmetic worked out and the code section named, so you learn the trap and not just the answer. No account.

Start the free practice testSee the $79 question bank

All questions here are original. They are not actual exam questions, and no question bank can promise you a pass.

What this page cites

Built and maintained by Jeff Clerisier, Trojan Digital Marketing.

Every rule here is cited to the section it comes from, and corrections are logged in public with the date. This is study material rather than electrical advice, and it does not replace your own code book or your inspector.

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