The CPA exam, the FINRA Series exams and the Enrolled Agent exam all ban personal calculators and give you one inside the testing software instead, so there's nothing to buy. The CPA exam adds a spreadsheet in the task-based simulations. What you get on exam day should shape how you practice.
I build exam prep for a living, and candidates for these three exams often spend time shopping for a calculator they aren't allowed to bring.
CPA: an on-screen calculator and a spreadsheet
You can't bring any calculator to the CPA exam, and your personal belongings, phone included, go in a locker. Inside the software you get two tools: an on-screen calculator, available during both the multiple-choice questions and the task-based simulations, and a spreadsheet tool in the simulations that looks and behaves like Microsoft Excel, with common formulas such as SUM, AVERAGE, PV and FV.
The on-screen calculator computes left to right and ignores order of operations. Enter 2 plus 3 times 4 and it returns 20, not 14. For any calculation with mixed operations, use the spreadsheet, which does follow order of operations, or break the calculation into steps.
FINRA Series and Enrolled Agent exams
The SIE and the Series exams (including the Series 6, 7, 63, 65, 66 and 79) don't let you bring a personal calculator. At a Prometric test center you're given a basic, non-programmable, non-printing calculator along with dry-erase boards for scratch work, and if you test online, a four-function calculator is available on screen. The Series exams aren't calculation-heavy, so there's nothing to learn in advance beyond getting comfortable with basic on-screen entry.
The IRS Enrolled Agent exam (the Special Enrollment Examination) gives you an on-screen calculator that works like the standard Windows calculator, available on every question. As of March 1, 2026, the EA exam is administered by PSI Services rather than Prometric, with 2026 testing rolling out from July. The on-screen calculator is still a standard four-function tool, so the change doesn't affect how you prepare.
How to practice
For the CPA exam, practice with a basic on-screen calculator and a spreadsheet, and drill the left-to-right quirk until you never trust the calculator on a mixed-operation problem, so it doesn't cost you a scored question. For the Series and EA exams, a plain four-function calculator (even the one on your computer) is close to what you'll be given.
FreeFellow's CPA, Series and EA question banks are free and include full step-by-step solutions, so you can practice the calculations the way you'll do them on exam day without buying hardware you can't use.