# ACT Math Formulas You Must Memorize (2026 Enhanced ACT)
Author: Team Catalyst
Author URL: https://catalysttestprep.com/blog/author/team-catalyst
Published: 2026-10-16
Category: Study Tips
Category URL: https://catalysttestprep.com/blog/category/study-tips
Meta Title: ACT Math Formulas You Must Memorize (2026 Enhanced ACT)
Meta Description: The ACT hands you no formula sheet. Here are the ACT math formulas worth memorizing, weighted to the enhanced test, and the ones ACT says you can skip.
Tags: ACT Prep, Math Equations To Know For, Act Vs Sat Math, Formulas For Math Sat
Tag URLs: ACT Prep (https://catalysttestprep.com/blog/tag/act-prep), Math Equations To Know For (https://catalysttestprep.com/blog/tag/math-equations-to-know-for), Act Vs Sat Math (https://catalysttestprep.com/blog/tag/act-vs-sat-math), Formulas For Math Sat (https://catalysttestprep.com/blog/tag/formulas-for-math-sat)
URL: https://catalysttestprep.com/blog/act-math-formulas

The ACT hands you nothing. No reference sheet, no formula box, no list in the margin. The SAT does the opposite: College Board's own Bluebook documentation says [a reference sheet with commonly used formulas appears on all tests with math questions](https://bluebook.collegeboard.org/students/tools). So the **ACT math formulas** you walk in carrying are the only ones you get, and that asymmetry is why students who prepped for the SAT first lose points on ACT geometry they could have done at thirteen.

The usual response is a list of thirty-one or thirty-two formulas. That response is wrong twice over, and this post explains why, then gives you the short list that replaces it.

## Key Takeaways

- **The ACT provides no formula sheet at all.** The SAT provides one on every math question. Prep for the ACT as if the geometry reference sheet does not exist, because it does not.
- **ACT says in writing that complex formula recall is not required.** Its own test description states that basic formulas are assumed but "recall of complex formulas and extensive computation are not required." The long cheat sheets contradict the test maker.
- **The enhanced ACT rebalanced the math section toward higher math.** Preparing for Higher Math is now 80 percent of the section and Integrating Essential Skills only 20 percent, so lists sized for the old test over-weight arithmetic and percentages.
- **Geometry is the only category where the formula is the whole answer.** At 17 to 20 percent it is where memorization pays, and it is exactly what the SAT reference sheet used to cover for you.
- **Four of the 45 math questions are never scored.** ACT reports 41 operational questions plus 4 field-test items, so a few of the hardest things you see on test day count for nothing.

## Does the ACT give you a formula sheet?

No. There is no reference sheet, no formula page in the booklet, and no formula panel on the screen in online testing. Whatever you need, you bring.

![Comparison board showing which math tools each exam provides: the SAT row holds four filled tiles for Desmos calculator, reference sheet, option eliminator and line reader, while the ACT row holds one filled calculator tile and three empty dashed tiles](https://prod.superblogcdn.com/site_cuid_cmrvvavb6000d01w5ghhmk0yd/images/act-vs-sat-math-test-day-tools-provided-1792150286139-compressed.png)The SAT supplies a formula reference on every math question. The ACT supplies a calculator and nothing else, which is why SAT-first students lose ACT geometry points.

This matters more than it sounds. A student who prepared for the SAT learned, correctly, that there was no point memorizing the volume of a cone, because the sheet was right there. That habit is a liability on the ACT. The formulas most likely to cost an SAT-trained student points are not the exotic ones. They are areas, volumes and special right triangles: the twelve or so items College Board decided were so basic it would simply give them to you.

## What does ACT actually say you need to know?

This is the part nobody quotes, and it is the most useful sentence ACT has published about its math section. From [ACT's own description of the mathematics test](https://www.act.org/content/act/en/products-and-services/the-act/test-preparation/description-of-math-test.html):

> "Knowledge of basic formulas and computational skills are assumed as background for the problems, but recall of complex formulas and extensive computation are not required."

Read it twice. The test maker is telling you that complex formula recall is not being measured. It also confirms on the same page that "you may use a calculator on the mathematics section," with no no-calculator portion anywhere in the enhanced format.

So a page-one article selling you thirty-two formulas to commit to memory is selling you work against the published specification. In practice the ACT behaves the way that sentence describes: where a question genuinely turns on an unusual formula, the formula tends to appear in the question stem, because the question is testing whether you can use it, not whether you stored it. That is a teaching observation rather than an ACT guarantee, but it is consistent with what ACT says it is doing.

## Where the formulas actually live on the enhanced ACT

The second reason the long lists are wrong is that they were sized for a test that no longer exists. The enhanced ACT, which reached all national testers from the September 2025 administration, reports math under two categories. ACT publishes the weights:

![Five-row board of enhanced ACT math reporting categories with weight ranges and a verdict for each: Algebra 17 to 20 percent, Functions 17 to 20 percent, Geometry 17 to 20 percent highlighted as formula-decisive, Statistics and Probability 12 to 15 percent, Number and Quantity 10 to 12 percent](https://prod.superblogcdn.com/site_cuid_cmrvvavb6000d01w5ghhmk0yd/images/enhanced-act-math-domain-weights-formula-verdict-1792150294436-compressed.png)Only one of the five higher-math categories is decided by whether you recalled a formula. Geometry is also the one the SAT reference sheet used to cover.Reporting categoryShare of the sectionIs a memorized formula decisive?Algebra17 to 20%Partly. One formula, the quadraticFunctions17 to 20%Rarely. Notation and reading, not recall**Geometry****17 to 20%****Yes. This is the memorization lane**Statistics and Probability12 to 15%Two definitions, mean and probabilityNumber and Quantity10 to 12%NoIntegrating Essential Skills20%No. Rates and percentages, not formulas

The five higher-math subcategories together make up the 80 percent that ACT labels Preparing for Higher Math. Integrating Essential Skills, the rates-and-percentages material, is the remaining 20 percent. On the pre-2025 ACT those proportions were close to 57 to 60 percent and 40 to 43 percent respectively, so the essential-skills half of the old test has been roughly halved and higher math has absorbed the difference.

Follow that through. Memorization only pays where the formula is the answer rather than the setup, and on this blueprint that is almost entirely Geometry, plus one formula in Algebra and two definitions in Statistics. That is a dozen items, not thirty-two.

Not sure where your teen stands? A free consultation with Catalyst Test Prep maps exactly which ACT math reporting category is costing them the most points, so you are never guessing about study time.

[Book a Free Consultation →](https://www.catalysttestprep.com/book-a-free-consultation?utm_source=blog&utm_medium=catalyst&utm_campaign=act-math-formulas)

## The ACT math formulas to memorize, in three groups

Group them by why you need them, not by topic. A student who understands why an item is on the list retrieves it faster under a sixty-seven-second clock.

![Portrait reference poster of twelve ACT math formulas arranged in three labelled groups: the SAT reference sheet set covering circle area, circumference, Pythagoras and the two special right triangles; coordinate geometry covering slope, midpoint, distance and the circle equation; and sequences and trigonometry covering SOHCAHTOA, the quadratic formula, arithmetic and geometric nth terms](https://prod.superblogcdn.com/site_cuid_cmrvvavb6000d01w5ghhmk0yd/images/act-math-formulas-to-memorize-three-groups-1792150313078-compressed.png)Twelve items in three groups. Group 1 is the set the SAT gives away and the ACT does not, which is where SAT-first students lose points.

### Group 1: the set the SAT would have handed you

These are the formulas on College Board's reference sheet. They are basic, which is exactly why they are dangerous: nobody revises them, and the ACT asks about them anyway.

- **Circle:** area = πr², circumference = 2πr
- **Triangle:** area = ½bh, and the three interior angles sum to 180°
- **Pythagorean theorem:** a² + b² = c²
- **Special right triangles:** the 30-60-90 sides go x, x√3, 2x; the 45-45-90 sides go x, x, x√2
- **Volumes:** rectangular solid lwh, cylinder πr²h, cone ⅓πr²h, sphere ⅔πr³

The special right triangles earn their place twice. They let you skip Pythagoras entirely on a large share of geometry questions, and they are the fastest route into basic trigonometry values.

### Group 2: coordinate geometry, which neither test gives you

Four formulas cover nearly all of it, and three of the four are the same idea applied differently.

- **Slope:** m = (y₂ − y₁) / (x₂ − x₁)
- **Midpoint:** ((x₁ + x₂)/2, (y₁ + y₂)/2)
- **Distance:** √((x₂ − x₁)² + (y₂ − y₁)²)
- **Circle in the plane:** (x − h)² + (y − k)² = r², centre (h, k), radius r

Notice that distance is Pythagoras wearing coordinates, and the circle equation is distance set equal to a constant. Learn them as one idea with three uses and you stop mixing up midpoint and slope, which is the single most common coordinate error we see in diagnostics.

Two facts belong here rather than in a formula: perpendicular lines have slopes that are negative reciprocals, and parallel lines have equal slopes. Students who memorize these as words get them right more often than students who memorize them as symbols.

### Group 3: the three that decide the hardest questions

- **SOHCAHTOA:** sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent
- **Quadratic formula:** x = (−b ± √(b² − 4ac)) / 2a, with the discriminant b² − 4ac memorized separately
- **Sequences:** arithmetic nth term aₙ = a₁ + (n − 1)d, geometric nth term aₙ = a₁ × rⁿ⁻¹

Memorize the discriminant as its own object, not as a part of the quadratic formula. ACT questions asking how many real solutions an equation has can be answered from the sign of b² − 4ac without solving anything, which turns a ninety-second question into a fifteen-second one.

The sequence formulas are on the list for a different reason: the arithmetic one is easy to reconstruct and the geometric one is not. Under time pressure students who try to rebuild the geometric term get the exponent wrong, using rⁿ instead of rⁿ⁻¹, and land on a wrong answer that is present among the choices.

## What should you not bother memorizing?

Three categories, and cutting them is what makes the short list possible.

**Anything ACT would class as complex.** The law of cosines is the clearest example. It appears rarely, and when a question needs it the formula is usually supplied. Learn the law of sines and law of cosines well enough to recognise and apply them if they appear in front of you, and stop short of drilling them to recall.

**Logarithm identities beyond the definition.** Knowing that logₖ(x) = y means b⁾ = x handles most ACT logarithm questions. The product, quotient and power rules are worth understanding and not worth flashcarding.

**Anything your calculator does faster.** ACT permits a calculator on every math question, so the formulas worth memorizing are the ones that tell you _what to compute_, not the ones that do the computing. Check ACT's current calculator policy before test day, since prohibited models are refused at the door.

There is one more thing worth knowing about what counts. ACT reports the math section as 41 operational questions plus 4 field-test items, so four of the 45 questions you answer are being trialled for future tests and contribute nothing to your score. You cannot identify which, and that is the point: a question that feels impossibly obscure may simply not be real. Answer it, move on, and do not let it rearrange your pacing.

## How do you memorize them so they survive test day?

Rereading a formula sheet produces recognition, not recall, and the ACT tests recall. Three mechanisms that work better, in the order to use them:

1. **Write the list from blank paper, timed.** Give yourself four minutes and reproduce all twelve from memory. Mark what you missed. Repeat the next day, writing only what you missed. Most students reach a complete list in four or five sessions, and the gaps are consistent: cone volume and the geometric nth term.
2. **Attach each formula to one question you got wrong.** A formula stored next to a specific failure is retrieved faster than one stored next to its own name. When you review a practice section, write the formula at the top of the question you missed, not in a notebook.
3. **Do a sixty-second retrieval drill before every practice section.** Not a review, a retrieval: state the twelve out loud or on paper, then start the timer. The habit of pulling them from memory is the skill being trained, and it transfers to test day in a way that reading does not.

If your teen can state a formula when asked but cannot produce it inside a timed section, that is not a knowledge gap and more revision will not fix it. It is a retrieval gap, and it responds to drills like the ones above. Our guide to [reviewing a practice test properly](https://catalysttestprep.com/blog/how-to-review-an-sat-practice-test) covers the review half of this in more detail, and the method transfers directly from the SAT to the ACT.

## One deadline to put in the calendar

Formulas are a four-week project. Registration is a one-day project with a hard edge, and the edge is close. According to [ACT's published national test dates](https://www.act.org/content/act/en/products-and-services/the-act/registration/test-dates.html), the next ACT is **12 December 2026**:

- Regular registration closes **6 November 2026**
- Late registration closes **29 November 2026**
- Photo upload and standby deadline **7 December 2026**
- Paper scores begin releasing **22 December 2026**

**There is no November ACT.** The seven national dates run September, October, December, February, April, June and July, so a student who misses the December registration windows is not waiting four weeks for the next sitting. They are waiting until 27 February 2027. If a December score needs to reach anywhere, read [how to change or cancel an ACT registration](https://catalysttestprep.com/blog/change-or-cancel-act-registration) before the deadline rather than after it.

Two final notes for anyone reading an older score chart. The enhanced ACT Composite now averages English, math and reading only, because science became optional. And the math section runs 45 questions in 50 minutes with four answer choices per question rather than five, which makes a blind guess a one-in-four shot instead of one-in-five. If you are sitting both tests, [our companion piece on SAT math formulas](https://catalysttestprep.com/blog/sat-math-formulas-you-need-to-know) sets out what the SAT reference sheet does and does not cover, and [what counts as a good ACT score](https://catalysttestprep.com/blog/what-is-a-good-act-score) puts the result in percentile terms.

## The short version

The ACT gives you no formulas, which sounds like a reason to memorize more and is actually a reason to memorize better. ACT's own specification rules out complex recall. The enhanced blueprint concentrates the section in higher math and leaves Geometry as the one category a remembered formula decides. Twelve items cover it, the first five of them are the ones the SAT would have printed beside the question, and the way to own them is timed blank-paper recall rather than rereading a list.

Do that, register before 6 November, and the formula half of ACT math stops being a source of lost points.

Ready to turn a prep plan into real score gains? Catalyst's 1:1 live online ACT and SAT programme starts with a free consultation to benchmark your teen's starting point and build a personalised path to their goal score. Tutors score in the 99th percentile, and the programme carries a 150 point improvement guarantee measured from your opening diagnostic, or your money back. Confirm the current terms at enrolment.

[Book a Free Consultation](https://www.catalysttestprep.com/book-a-free-consultation?utm_source=blog&utm_medium=catalyst&utm_campaign=act-math-formulas)

Sources checked 16 October 2026: ACT description of the mathematics test, ACT national test dates and deadlines, ACT understanding your scores, ACT student blog on the enhanced ACT, College Board Bluebook testing tools.
## FAQs
Q: Does the ACT give you a formula sheet?
A: No. The ACT provides no formula reference of any kind on the math section. This is the single biggest difference from the SAT, where College Board's Bluebook app states that a reference sheet with commonly used formulas appears on all tests with math questions. On the ACT, every formula you use has to come from memory or be supplied inside the question itself.

Q: How many ACT math formulas do I actually need to memorize?
A: Far fewer than the thirty-plus lists suggest. Around a dozen carry almost all the value: the circle and triangle area formulas, Pythagoras, the two special right triangles, slope, midpoint, distance, the circle equation, SOHCAHTOA and the arithmetic and geometric sequence terms. Everything else is either rarely tested or given to you in the question.

Q: How long is the ACT math section on the enhanced test?
A: Forty-five questions in fifty minutes, which works out at about sixty-seven seconds each. That is slower per question than the old sixty-in-sixty format, so the enhanced test gives you marginally more thinking time rather than less. Of the forty-five questions, forty-one are scored and four are unscored field-test items.

Q: Is the quadratic formula on the ACT?
A: Yes, and you have to know it, because nothing on the ACT supplies it. Memorize the discriminant separately as b squared minus 4ac, because questions about how many real solutions an equation has can be answered from the discriminant alone without solving anything.

Q: Do I need trigonometry for the ACT?
A: Yes. Geometry carries 17 to 20 percent of the enhanced ACT math section and right-triangle trigonometry sits inside it. SOHCAHTOA covers most of what appears. The law of sines and law of cosines show up less often, and when a question genuinely needs one it will often give it to you.

Q: What is the difference between ACT and SAT math formulas?
A: The mathematics overlaps heavily. The difference is access. The SAT shows you a geometry reference sheet beside every math question, so SAT prep can reasonably skip memorizing areas and volumes. The ACT shows you nothing, so an SAT-trained student walks into the ACT missing exactly the formulas the SAT used to supply.

Q: Can I use a calculator on ACT math?
A: Yes. ACT states that you may use a calculator on the mathematics section, and unlike the old format there is no no-calculator portion. Check ACT's current calculator policy before test day, because prohibited models are turned away at the door and the list is updated periodically.

Q: When is the next ACT and when do I need to register?
A: The next national ACT is 12 December 2026. Regular registration closes 6 November, late registration 29 November, and the photo upload and standby deadline is 7 December. There is no November ACT, so missing 6 November means waiting until 27 February 2027.

Q: How does Catalyst Test Prep teach ACT math formulas?
A: Not as a list to recite. A Catalyst diagnostic shows which formulas a student already retrieves under time pressure and which ones they can state but cannot deploy, and the 1:1 sessions then drill only the gap. Tutors score in the 99th percentile, and the programme carries a 150 point improvement guarantee measured from that first diagnostic, or your money back. Confirm the current terms at enrolment.

Q: How do I get started with ACT math prep?
A: Book a free consultation. It takes about half an hour, it maps which of the five ACT math reporting categories is actually costing your teen points, and it produces a study plan built from that evidence rather than from a generic formula list. There is no obligation to enrol afterwards.




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