SAT Math Formula Sheet

Many students are blown away by the fact that every SAT Math Section has a geometry cheat sheet at the very beginning (hopefully, they pick up on this before they take the actual test).

Today, I’m going to do better than just rehash those formulas. I’m going to tell you which ones you should memorize (since it’ll make you faster on test day) and which ones you can refer back to (since you don’t want to cram more unnecessary information in your head).

Math formulas provided for you on the SAT

abstract shapes

1. Circumference and area of a circle

Recall this formula as naturally as you can recall your home address. It’s easy:

Area = πr^2

Circumference = 2πr

And don’t mix the two up!

2. Area of a rectangle

This one should be pretty intuitive. To find the area of a rectangle/square multiply length x width (they are the same in a square). Perimeter, which is not part of the SAT cheat sheet, is found by adding the length and width and multiplying by 2.

3. Area of a triangle

It’s 1/2 of the base x the height. Don’t waste time flipping the pages back and forth. Know this cold.

4. Volume of a box

Don’t memorize this—just refer back to the page if necessary. One thing you don’t get is the surface area of a box. For a cube, things are much easier: volume is s^3, in which s = the side; surface area is 6s^2.

5. Cylinder

You probably won’t see a problem relating to a cylinder. Anyhow, it’s not that easy to memorize. So it’s great to see it as part of the cheat sheet at the beginning of each section.

6. Pythagorean Theorem

Know this cold. And be fluent and being able to find the missing sides.

7. 30:60:90 triangle

Don’t feel you have to know this cold, though it will make things faster. Just make sure you know what everything stands for when you refer to the diagram.

8. 45:45:90

As a tutor, I always want to make sure my students know this well. But at the end of the day, if you don’t know memorize the formula, you can just use the cheat sheet. Just make sure you know how the sides are connected.

For instance, sometimes you can have a √2 as one of the sides. The relationship between the two equal sides and the hypotenuse is that the hypotenuse will always be √2 times greater.

Formulas not on the SAT’s math cheat sheet

illustrated formula for the volume of a sphere

  • Volume of a cone: 1/3 πr^3
  • Volume of a sphere: 4/3 πr^3
  • Average: Total/# of numbers (This is the only non-geometry formula. It’s very important that you know this. I’d recommend memorizing it, or at least understand how it is derived).
  • Length of the longest possible line you can draw between two points in a cube: s√3



  • Chris Lele

    Chris Lele is the Principal Curriculum Manager (and vocabulary wizard) at Magoosh. Chris graduated from UCLA with a BA in Psychology and has 20 years of experience in the test prep industry. He's been quoted as a subject expert in many publications, including US News, GMAC, and Business Because. In his time at Magoosh, Chris has taught countless students how to tackle the GRE, GMAT, SAT, ACT, MCAT (CARS), and LSAT exams with confidence. Some of his students have even gone on to get near-perfect scores. You can find Chris on YouTube, LinkedIn, Twitter and Facebook!

By the way, Magoosh can help you study for both the SAT and ACT exams. Click here to learn more!

, ,

No comments yet.

Magoosh blog comment policy: To create the best experience for our readers, we will only approve comments that are relevant to the article, general enough to be helpful to other students, concise, and well-written! 😄 Due to the high volume of comments across all of our blogs, we cannot promise that all comments will receive responses from our instructors.

We highly encourage students to help each other out and respond to other students' comments if you can!

If you are a Premium Magoosh student and would like more personalized service from our instructors, you can use the Help tab on the Magoosh dashboard. Thanks!

Leave a Reply