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Checked against primary sources 2026-09-04
Two Michigan Exam Calculators: Transformer and Ohm's Law
Both calculators print every step of the working, because the working is what you'll have to reproduce at PSI with no calculator in reach. They hold 2026 values, and wherever the 2023 book Michigan tests on uses a different section number, they print both numbers.
What each calculator does
Transformer calculator. Put in the kVA and the voltages and it converts to amps on the primary and the secondary, then works the overcurrent protection for each side from the percentages.
Ohm's law calculator. Give it any two of voltage, current, resistance and power and it returns the other two, with single phase and three phase power handled as separate calculations.
Electrical theory is the one content area where the open book won't help you on the day, so the Ohm's law calculator is the one to start drilling early.
The edition behind the numbers
Both calculators were built on the 2026 National Electrical Code, and Michigan's papers are written on the 2023 edition. That gap shows up in two places, the section numbers and the values inside the tables.
Section numbers. Where a section a calculator cites has a different number in the 2023 book, the calculator prints the 2023 number beside it. Table 310.16 keeps its number in both books, and our renumbering record has no entry for Article 310.
Table values. We read the values out of the 2026 tables and haven't compared them row by row against a 2023 printing. Use the calculators to learn the method, and check any value that decides an answer in the 2023 book you carry into the room, since that's the book the paper is written against.
Where the 2023 and 2026 numbers part ways
Each calculator names one section that carries a different number in the 2023 book, and each prints the 2023 number next to the 2026 one.
- The transformer calculator cites overcurrent protection for transformers at 450.5 in the 2026 book, which is 450.3 in the 2023 edition Michigan tests on.
- The Ohm's law calculator points at load calculations in Article 120 of the 2026 book, which is Article 220 in the 2023 edition.
The other sections they rely on read the same in both editions, among them 240.4(D), 240.6 and Table 310.16.
The page on the tested edition lists every section that changed address between the books, including the many that neither calculator touches.
Turning the working into points on paper
Calculators are on the PSI bulletin's list of prohibited electronic devices, so anything you practice here has to carry over to working by hand. That is the reason each result shows its steps.
Work each problem on paper first, then run it through the calculator and compare the two line by line. A total that doesn't match only tells you something went wrong, and the first line where the two disagree tells you which step it was.
Keep a log of the steps you miss. After a couple of weeks the log shows which steps keep costing you, and those are the ones to drill before your date.
Questions people ask
Are these Michigan electrician exam calculators free to use?
Yes, both of them, with no account and nothing locked. Nothing you type into either calculator leaves your browser.
Can you take a calculator into the Michigan electrician exam?
No. The PSI bulletin lists calculators among the prohibited electronic devices, and they go into secure storage before you enter the room. The bulletin doesn't say what the workstation offers in their place, so call PSI on 855-579-4635 and ask before your date.
Which NEC edition do these calculators use?
Their table values come from the 2026 edition. Where a section number differs in the 2023 book, the calculator prints the 2023 number beside it. Before an answer rides on a value, check that value in the 2023 book you'll carry into the exam.
Which calculator section numbers differ between the 2023 and 2026 code?
One in each. The transformer calculator cites 450.5 from the 2026 book, which is 450.3 in the 2023 edition Michigan tests on, and the Ohm's law calculator points at Article 120 for load calculations, which is Article 220 in the 2023 edition.
Do these calculators replace the code book?
No. They're study material for learning the method and the order of the steps. The exam is open book on the 2023 edition, and the book on your desk has the final say on every value.
30 free timed items, worked on every miss
Get one wrong and the review lays out the arithmetic, the section it rests on and the trap that caught you. You won't need an account.
The items are written on the 2026 code. Wherever a number moved, the 2023 number Michigan still tests is printed beside it.
What this page cites
- PSI's Michigan candidate information bulletin In effect from 20 August 2026 and read on 4 September 2026. The item counts, time limits, 75 percent passing standard, $100 fee, allowed references, book and conduct rules, attempt limit, score report and test center list cited on this site all come from it. source
- LARA exam and licensing page, Bureau of Construction Codes The state page naming the code each examination is based on and the experience each license calls for. Read 4 September 2026. source
- 2023 to 2026 renumbering record The list we keep of articles and sections that carry a different number in the two editions. Each entry was checked in the 2026 text before it was added.
- Part 8 Electrical Code rules, R 408.30801 to R 408.30880 Michigan's adopting rule, which puts the NEC into force in the state and writes in the state's own amendments. Read on the state administrative rules site, 4 September 2026. source
The book that counts on exam day is your own unmarked copy of the National Electrical Code. Michigan's papers stay open book on the 2023 edition until the PSI bulletin names a newer one.
Every practice item on this site was written here, and none of them came off a real Michigan paper.
Both NEC and National Electrical Code are trademarks registered to the National Fire Protection Association, the body that also holds the copyright in the code.
Trojan Digital Marketing publishes this site on its own. It has no affiliation with NFPA, LARA, the Michigan Bureau of Construction Codes, PSI Services or any licensing authority, and none of them endorses or sponsors it.