The best calculator for the ACT is the allowed model you already know well, not the one with the longest feature list. On Math, a familiar graphing or scientific calculator can speed up messy arithmetic and quick checks. A fancy device you fumble under time pressure usually costs more points than it saves.
Familiarity beats features
Students often ask which brand is "best," as if a better chip raises a Math score. It does not. What raises your score is solving problems cleanly, and that means knowing when to calculate, how to enter an expression without typos, and how to check a graph or table in a few seconds. If you have practiced with a TI-84-style calculator all year, that is usually a stronger choice than a brand-new model you open the night before the test.
The same idea applies if you prefer a solid scientific calculator. If you can evaluate expressions, convert fractions, and move quickly without hunting menus, you are ahead of someone with a graphing calculator who still pauses on every keystroke. Features only help when your fingers already know them.
Confirm the rules before you buy or pack
ACT permits many graphing and scientific calculators, bans some models (including CAS models such as the TI-89), allows calculators only on Math, and expects you to bring your own. Policies can change, so always confirm the current list and rules on act.org before test day. Our overview of the ACT calculator policy covers the practical checklist without pretending to replace the official page.
Guides in this calculator cluster
Once you have a permitted model you know well, use these guides to build better habits around it:
- ACT calculator policy: Math only, bring your own, approved versus banned models, and why act.org is the source of truth.
- When not to use your calculator on the ACT: mental math, plug-in strategies, and when graphing wastes time.
- ACT calculator shortcuts: graphing, TABLE, intersect or solver tools, and fraction habits worth practicing before test day.
- TI-84 tips for the ACT: concrete workflows if that is the device you will bring.
- Can you use Desmos on the ACT?: hardware versus phone or app, and how to check what is currently allowed.
A common, reliable choice
Many students land on a TI-84 family calculator because classrooms and practice materials often assume that layout. That shared familiarity is useful, but it is not magic. A scientific calculator that is clearly permitted and that you use every practice session can be just as strong for a student who does not need graphing. The wrong move is buying a new model for features you will not practice under timed conditions.
If you are still deciding, pick something you can borrow or already own, confirm it is allowed, and commit to it for the rest of your prep. For Desmos-branded options, do not guess from social media posts. Check act.org for which products, if any, are currently permitted, and read our Desmos guide above before you plan around a phone app that may not belong in the testing room.
Practice with the exact device you will bring
Use your test-day calculator on timed Math sections, not only on homework. Learn the few moves that actually help: clean fraction entry, a quick table of values, graphing to check an intersection, and storing a value so you do not retype a long decimal. Leave the deep menus alone until those basics feel boring. On thirty-six, keep the same device in your hand so muscle memory transfers when the clock is real.
Pack backups, then get back to Math
Fresh batteries and, if you can, a spare permitted calculator you also know how to use prevent a quiet disaster mid-section. Add the calculator to what to bring to the ACT, then put most of your energy back into content: formulas, algebra fluency, and miss review. A calculator supports Math. It does not replace how to improve your ACT Math score.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.