ACT Calculator Policy 2026: What You Can Use, Bring, and Practice With

The calculator question usually shows up at the worst time: you are packing for the ACT, someone says their calculator is banned, and suddenly you are searching a model number instead of sleeping.

Here is the short answer: you may use a permitted 4-function, scientific, or graphing calculator on ACT Math only. A calculator with computer algebra system (CAS) functionality is not allowed, and an online ACT includes Desmos in the testing platform during Math. You still need a plan for the format you are actually taking.

Do not turn this into a hunt for the “best” calculator. Your job is simpler: bring a permitted tool you know how to use, remove anything the policy requires you to remove, and practice the few moves that genuinely save you time.

A calculator should make a good setup faster. It cannot choose the setup for you.

Start With Your Testing Format

The same ACT policy applies to your handheld calculator, but your test format changes the tools available to you. Before choosing what to practice, check your MyACT registration and your test-center instructions.

Do not assume an online test means you should leave your handheld calculator at home. ACT says students taking the test online have access to Desmos, while its calculator policy also says students must bring their own permitted calculator. Read your registration instructions and bring a permitted, familiar handheld calculator unless those instructions tell you otherwise.

The 60-Second Permission Check

Run this check with the actual calculator you plan to bring. If any answer is unclear, use the official policy—not a resale listing, a class group chat, or a memory from another test.

1. Is it only for Math? ACT allows calculators on the Mathematics test, not English, Reading, Science, or Writing.
2. Is the model in an allowed category? A 4-function, scientific, or graphing model is generally permitted unless it falls under a prohibited rule or model list.
3. Does it have CAS functionality? If it has built-in or downloaded CAS functionality, it is prohibited. Common named examples include TI-89 and TI-92 models, TI-Nspire CAS, HP Prime, HP 48GII, HP 40G/49G/50G models, and several Casio ClassPad and Algebra fx models.
4. Does it contain documents or a CAS app/program? Remove all documents and remove every program or app with CAS functionality. ACT says a “Press to Test” setting or another disabled mode is not a substitute for removing prohibited programs.
5. Does it need a physical change? Remove paper tape and power cords, turn off sound, and completely cover an infrared data port with heavy opaque material when applicable.
6. Can you use it calmly? Charge it or install reliable batteries, then work a few timed questions with it before calling the decision finished.

A non-CAS TI-Nspire is permitted; a TI-Nspire CAS is not. That one-letter difference is exactly why “it looks like the calculator my friend uses” is not a useful test.

What CAS Means—and What It Does Not

CAS stands for computer algebra system. ACT describes it as functionality that can solve equations algebraically, simplify expressions, perform algebraic manipulations, or do exact arithmetic. If you are not sure whether an installed app or program crosses that line, ACT’s guidance is to remove it or not install it before test day.

This is where students often overcorrect. ACT does not say every saved math program is banned. Its FAQ says a single-purpose math program can be allowed when it uses the calculator’s own language and stays within the policy’s limits. But documents must be removed, CAS programs must be removed, and a program must not call another program. If you do not know how a program works, do not make test morning the time to decide.

Build a Calculator Plan, Not a Calculator Dependency

ACT says every Math problem can be solved without a calculator. That does not mean you should avoid one. It means your calculator should support your reasoning rather than replace it. A good plan tells you when to reach for it and when not to.

The diagnostic rule is simple: if you keep getting a number that does not match any answer choice, pause before pressing more buttons. Write the relationship, label the quantity the question asks for, then re-enter only after you can explain what each number means. Most calculator misses start before the first keystroke.

A Three-Session Rehearsal Before Test Day

You do not need to master every menu. You need proof that your chosen setup helps under ACT timing. Use three short sessions instead of a last-minute tutorial binge.

1. Session 1: Permission and reset. Confirm the exact model, remove documents and prohibited functionality if needed, turn off sound, and make sure the calculator has power. Put the official policy link in your test-day checklist.
2. Session 2: Learn two useful moves. In official practice, choose two actions you will actually use—such as graphing an equation to inspect an intersection or evaluating a messy calculation. Write down when each move helps and when it wastes time.
3. Session 3: Timed transfer. Do a short mixed Math set with the exact tool you will use. Mark every question where the calculator helped, slowed you down, or hid a setup mistake. Keep one rule for the next set.

ClassVal fits most naturally in the third session: take a short targeted Math set after you identify the kind of decision that is breaking down, then retest the same decision in a mixed timed set. The goal is not to use a calculator on more questions. It is to make fewer avoidable mistakes on the questions where it belongs.

Your Night-Before ACT Calculator Checklist

• Exact model checked: You verified the calculator against ACT’s current policy, not a general “ACT approved” product label.
• CAS and documents handled: Documents are removed; CAS apps or programs are removed rather than merely disabled.
• Physical setup handled: Sound is off, any required port covering is in place, and prohibited cords or tape are removed as applicable.
• Power covered: The calculator is charged or has reliable batteries. Bring a permitted backup and/or extra batteries if you have them.
• Format rehearsed: You practiced with Desmos if you are testing online and with your handheld calculator if you plan to use one.
• Math-only rule remembered: Put it away outside the Math section and do not share it during the test.
• Test-day basics packed: Admission ticket, acceptable photo ID, No. 2 pencils, and the device/charger if your registration requires them.

FAQ: ACT Calculator Rules

Can I use Desmos on the ACT?

Yes, if you are taking the ACT online: ACT says the testing platform includes the Desmos graphing calculator during the Math section. Practice with it before test day so you are not learning its controls under the clock.

Can I use a TI-84 on the ACT?

A TI-84 is not on ACT’s named prohibited list, but you should still check the exact model and its setup against the current official policy. Remove documents and any CAS functionality that may have been added before testing.

Can I use a TI-Nspire on the ACT?

ACT says the non-CAS TI-Nspire is permitted and the TI-Nspire CAS is prohibited. Confirm the exact model you own; do not decide based on the calculator’s appearance alone.

Can I use my calculator on ACT Science?

No. ACT’s calculator policy permits calculators on the Mathematics test only. Plan your Science timing and arithmetic without depending on a handheld or built-in calculator.

Do I need a graphing calculator for the ACT?

No. ACT allows 4-function, scientific, and graphing calculators when they meet the policy. Use the permitted tool you know best. A new graphing calculator is rarely a good trade if you have not practiced with it under time.

The Bottom Line

The ACT calculator policy is not a reason to panic-buy a device or memorize every feature. Check your exact model, clean up its setup, practice the tools you will really use, and let your math reasoning lead.

Your next step: take your calculator out now, run the 60-second permission check, and use it for one short timed Math set this week. If you cannot explain when a calculator helped on each question, your next practice block should be a smaller, clearer rehearsal.