Top 15 Formulas You Must Know for SAT Math Success

You don't need to memorize every formula in your textbook to score well on SAT Math—but you do need to know the right ones. The test leans on a core set of formulas that appear again and again across algebra, geometry, and data analysis questions.

In this guide, we'll walk through the top 15 SAT Math formulas you absolutely must know for test day. You'll see what each formula does, why it matters, and how to remember it. Use this as your SAT Math formula checklist as you prep.

How to Study SAT Math Formulas the Smart Way

Simply staring at a formula sheet the night before the SAT won't cut it. The goal isn't just memorization—it's being able to recognize when and how to use each formula under time pressure.

A smart formula study routine might include:

• Writing each formula by hand several times a week.
• Creating flashcards with a question on one side and the formula on the other.
• Doing targeted practice problems that use that specific formula.
• Reviewing your formula sheet for 5–10 minutes before every study session.

Now let's dive into the 15 formulas that will show up again and again on SAT Math.

Core Algebra Formulas for SAT Math

1. Slope of a Line: m = (y₂ − y₁) / (x₂ − x₁)

Slope measures how steep a line is—how much y changes when x increases by 1. You'll see slope in questions about graphs, rate of change, and linear models. Remember: positive slope means the line goes up, negative slope means it goes down.

2. Slope-Intercept Form: y = mx + b

This is the most important linear equation form on SAT Math. Here, m is the slope and b is the y-intercept (where the line crosses the y-axis). Many questions will give you a story, then ask you to build or interpret an equation in this form.

3. Point-Slope Form: y − y₁ = m(x − x₁)

If you know the slope and one point on a line, this form is your best friend. It's especially helpful on SAT Math when you're given one data point and a rate of change and need the equation of a line quickly.

4. Quadratic Formula: x = [−b ± √(b² − 4ac)] / (2a)

The quadratic formula solves equations of the form ax² + bx + c = 0. On the SAT, you might use it when factoring is messy or impossible. Don't forget that the expression under the square root, b² − 4ac, is the discriminant, which tells you how many real solutions there are.

5. Exponent Rules (Product & Power)

Two key rules pop up often in SAT Math questions involving growth, scientific notation, or exponential functions:

• aᵐ · aⁿ = aᵐ⁺ⁿ (same base, add exponents)
• (aᵐ)ⁿ = aᵐⁿ (power of a power, multiply exponents)

Being fluent with these lets you simplify expressions and compare exponential quantities quickly.

Geometry Formulas You Must Know for SAT Math

The SAT provides some geometry formulas in the reference box—but not all of them. And even the given ones won't help if you don't know when to use them. These are the must-know geometry formulas.

6. Area of a Rectangle: A = lw

This basic formula shows up in disguise in many word problems about rooms, fields, or diagrams. l is length and w is width. Watch units: if one side is in feet and the other in inches, you'll need to convert.

7. Area of a Triangle: A = ½bh

b is the base and h is the height (the perpendicular distance from the base). On SAT Math, sometimes the height is not drawn—you may have to spot that a side is perpendicular or imagine a dropped height.

8. Pythagorean Theorem: a² + b² = c²

This classic formula applies to right triangles, where c is the hypotenuse. Memorizing common Pythagorean triples like 3–4–5 and 5–12–13 can save you valuable time on SAT Math.

9. Circumference and Area of a Circle

Two circle formulas you will definitely need:

• Circumference: C = 2πr or C = πd
• Area: A = πr²

Questions might ask about arcs, sectors, or shaded regions—these all build off the basic circle formulas, so be comfortable with them.

10. Volume of a Rectangular Prism: V = lwh

Volume questions often involve boxes, tanks, or containers. Volume is the amount of space inside the shape. Pay attention to units—if you convert length to centimeters, your volume will be in cubic centimeters.

Statistics and Data Formulas for SAT Math

11. Mean (Average): mean = (sum of values) / (number of values)

SAT Math loves average questions, especially ones that involve adding or removing values and asking how the mean changes. Always think: total = mean × number of items. That relationship is often the secret to solving these quickly.

12. Distance Formula: d = √[(x₂ − x₁)² + (y₂ − y₁)²]

This is just the Pythagorean theorem in coordinate form. It's used to find the distance between two points on the coordinate plane. If you see two points and words like “distance” or “radius,” this formula is likely in play.

13. Midpoint Formula: ((x₁ + x₂)/2, (y₁ + y₂)/2)

The midpoint is the point exactly halfway between two points. SAT questions might ask for the midpoint directly or use it in geometry and coordinate proofs.

Percent and Growth Formulas for SAT Math

14. Percent Change: (new − old) / old × 100%

Percent increase and decrease questions show up all the time in SAT Math word problems involving prices, populations, and data. Always remember that you divide by the original amount, not the new one.

15. Simple Exponential Growth: final = initial × (1 ± r)ᵗ

Here r is the rate (as a decimal), and t is the number of time periods. This shows up in questions about interest, population, or repeated percentage changes. A growth of 8% per year becomes (1.08)ᵗ; a decrease of 12% becomes (0.88)ᵗ.

Turning Formulas into Higher SAT Math Scores

Knowing these 15 formulas is a huge step toward SAT Math success—but the real magic happens when you practice recognizing which formula fits which question. The more you work with real SAT-style problems, the faster this pattern recognition becomes.

That's where guided, adaptive practice comes in. Instead of guessing which formulas to review each day, you can use an AI tutor to diagnose your weak spots and keep putting the right formulas in front of you at the right time.