SAT Math Formulas: Every Formula You Need to Memorize for 2026

SAT Math Formulas: Every Formula You Need to Memorize for 2026

The Digital SAT provides a reference sheet with some basic formulas, but that sheet covers only a fraction of what you actually need to know. The formulas on the reference sheet are mostly geometry basics that you should already know — the formulas that separate a 650 from an 800 are the ones you must have memorized cold. Knowing which formula to apply, and applying it quickly without hesitation, is what turns hard questions into easy ones.

This guide covers every formula tested on the Digital SAT in 2026, organized by topic. For each formula, we explain when it appears and how to recognize questions that require it. For section-specific strategies, see our SAT Math 750+ Guide. For overall SAT preparation, see our Complete SAT Guide.

Formulas Given on the SAT Reference Sheet

The Bluebook app displays a reference sheet you can access during the Math section. These formulas are provided for you — you do not need to memorize them, but you should know them well enough that you do not waste time looking them up during the test:

• Area of a circle: A = pi * r^2
• Circumference of a circle: C = 2 * pi * r
• Area of a rectangle: A = l * w
• Area of a triangle: A = (1/2) * b * h
• Pythagorean theorem: a^2 + b^2 = c^2
• Special right triangles: 30-60-90 sides are x, x*sqrt(3), 2x; 45-45-90 sides are x, x, x*sqrt(2)
• Volume of a rectangular prism: V = l * w * h
• Volume of a cylinder: V = pi * r^2 * h
• Volume of a sphere: V = (4/3) * pi * r^3
• Volume of a cone: V = (1/3) * pi * r^2 * h
• Volume of a pyramid: V = (1/3) * l * w * h

Even though these formulas are provided, do not rely on looking them up during the test. Every second you spend navigating to the reference sheet is a second lost from problem-solving. Memorize the common ones (Pythagorean theorem, area of a circle, area of a triangle) so the reference sheet is only a backup for less common formulas like cone and sphere volumes.

Algebra Formulas (35% of SAT Math)

Algebra is the largest content area on the SAT, covering roughly 35% of all Math questions. These formulas must be automatic:

Linear Equations

• Slope-intercept form: y = mx + b, where m is the slope and b is the y-intercept
• Point-slope form: y - y1 = m(x - x1), useful when you know one point and the slope
• Standard form: Ax + By = C, where A, B, and C are integers
• Slope formula: m = (y2 - y1) / (x2 - x1) — rise over run between two points
• Parallel lines have equal slopes: m1 = m2
• Perpendicular lines have negative reciprocal slopes: m1 * m2 = -1

Systems of Equations

• One solution: Lines intersect at one point — different slopes
• No solution: Lines are parallel — same slope, different y-intercepts (coefficients are proportional but constants are not)
• Infinite solutions: Lines are identical — same slope and same y-intercept (all coefficients and constants are proportional)
• Elimination method: Multiply equations to make one variable's coefficients equal, then add or subtract
• Substitution method: Solve one equation for a variable and substitute into the other

Inequalities

• When multiplying or dividing by a negative number, flip the inequality sign
• Compound inequalities: a < x < b means x is between a and b
• Absolute value inequality: |x - a| < b means a - b < x < a + b
• Absolute value inequality: |x - a| > b means x < a - b OR x > a + b

Advanced Math Formulas (35% of SAT Math)

Advanced Math is equally weighted with Algebra and includes quadratics, polynomials, exponentials, and radicals.

Quadratic Equations

• Standard form: ax^2 + bx + c = 0
• Quadratic formula: x = (-b +/- sqrt(b^2 - 4ac)) / (2a) — works for every quadratic equation
• Discriminant: D = b^2 - 4ac — determines the nature of roots
• D > 0: Two distinct real solutions
• D = 0: One repeated real solution (the parabola touches the x-axis at exactly one point)
• D < 0: No real solutions (two complex solutions)
• Factored form: a(x - r1)(x - r2) = 0, where r1 and r2 are the roots (x-intercepts)
• Vertex form: a(x - h)^2 + k, where (h, k) is the vertex of the parabola
• Vertex from standard form: h = -b/(2a), then k = f(h)
• Sum of roots: r1 + r2 = -b/a
• Product of roots: r1 * r2 = c/a

The SAT frequently asks about the discriminant without using that word. Questions like 'how many solutions does the equation have?' or 'for what value of k does the system have no solution?' are discriminant questions in disguise.

Polynomial Functions

• Factor theorem: If f(a) = 0, then (x - a) is a factor of f(x)
• Remainder theorem: When f(x) is divided by (x - a), the remainder is f(a)
• A polynomial of degree n has at most n real roots (x-intercepts)
• End behavior: Even-degree polynomials with positive leading coefficient go up on both ends; odd-degree polynomials with positive leading coefficient go down-left and up-right

Exponential Functions

• Growth: y = a(1 + r)^t, where a is the initial value, r is the growth rate, and t is time
• Decay: y = a(1 - r)^t
• Continuous growth/decay: y = a * e^(kt), where k > 0 is growth and k < 0 is decay
• Doubling time: If y = a * 2^(t/d), the quantity doubles every d time units
• Exponent rules: a^m * a^n = a^(m+n), (a^m)^n = a^(mn), a^(-n) = 1/a^n, a^0 = 1

Radical and Rational Expressions

• sqrt(a * b) = sqrt(a) * sqrt(b)
• sqrt(a / b) = sqrt(a) / sqrt(b)
• a^(m/n) = n-th root of a^m
• Rationalizing the denominator: multiply numerator and denominator by the conjugate
• Rational expressions: find common denominators to add/subtract, cross-multiply to solve equations

Geometry and Trigonometry Formulas (15% of SAT Math)

Circles

• Standard form of a circle: (x - h)^2 + (y - k)^2 = r^2, where (h, k) is the center and r is the radius
• General form: x^2 + y^2 + Dx + Ey + F = 0 — complete the square to convert to standard form
• Arc length: s = (theta/360) * 2 * pi * r (for degrees) or s = r * theta (for radians)
• Sector area: A = (theta/360) * pi * r^2 (for degrees)
• Central angle theorem: The central angle is twice the inscribed angle that subtends the same arc
• Tangent line to a circle is perpendicular to the radius at the point of tangency

Triangles

• Sum of interior angles: 180 degrees
• Triangle inequality: The sum of any two sides must be greater than the third side
• Similar triangles: Corresponding sides are proportional, corresponding angles are equal
• Midpoint formula: M = ((x1 + x2)/2, (y1 + y2)/2)
• Distance formula: d = sqrt((x2 - x1)^2 + (y2 - y1)^2)

Trigonometry

• SOH-CAH-TOA: sin(theta) = opposite/hypotenuse, cos(theta) = adjacent/hypotenuse, tan(theta) = opposite/adjacent
• Key angle values: sin(30) = 1/2, cos(30) = sqrt(3)/2, sin(45) = sqrt(2)/2, cos(45) = sqrt(2)/2, sin(60) = sqrt(3)/2, cos(60) = 1/2
• Pythagorean identity: sin^2(theta) + cos^2(theta) = 1
• Complementary angles: sin(x) = cos(90 - x) and cos(x) = sin(90 - x)
• Radians to degrees: multiply by 180/pi. Degrees to radians: multiply by pi/180
• Unit circle: 360 degrees = 2*pi radians, 180 degrees = pi radians, 90 degrees = pi/2 radians

Problem-Solving and Data Analysis Formulas (15% of SAT Math)

Ratios and Proportions

• Direct proportion: y = kx (when one quantity increases, the other increases proportionally)
• Inverse proportion: y = k/x (when one quantity increases, the other decreases proportionally)
• Cross multiplication: If a/b = c/d, then ad = bc
• Percent change: ((new - old) / old) * 100

Statistics

• Mean: Sum of all values divided by the number of values
• Median: The middle value when data is sorted in order (average of two middle values if even count)
• Mode: The most frequently occurring value
• Range: Maximum value minus minimum value
• Standard deviation: A measure of spread — higher SD means data is more spread out from the mean. You do not need to calculate SD on the SAT, but you must understand what it measures and how to compare SDs between data sets
• Margin of error: Decreases as sample size increases. A 95% confidence interval means 95% of similarly drawn samples would produce results within that margin

Probability

• Basic probability: P(event) = favorable outcomes / total outcomes
• Complement: P(not A) = 1 - P(A)
• Independent events: P(A and B) = P(A) * P(B)
• Two-way tables: Read carefully — 'given that' language means conditional probability (restrict to the relevant row or column)

How to Study These Formulas

Memorizing formulas without understanding when to use them is pointless. Here is a practical approach:

1. Start with practice problems — Do not start by memorizing a list. Instead, work through SAT practice tests and note which formulas you needed but did not know. This identifies your actual gaps.

2. Create flashcards for your gaps only — If you already know slope-intercept form, do not waste time reviewing it. Focus flashcard study on formulas you consistently forget or misapply.

3. Practice applying, not reciting — For each formula, work at least 5-10 problems that require it. The goal is to recognize the question pattern and apply the formula automatically.

4. Use the Desmos calculator strategically — The built-in Desmos graphing calculator on the Digital SAT can verify your answers, graph functions to check your work, and solve equations. Practice using it alongside formulas, not instead of them.

5. Review weekly — Do a timed formula review every week during your study period. Gradually reduce the time you spend reviewing as formulas become automatic.

For a complete study plan that builds formula knowledge systematically, see our SAT Study Plan guide.

Practice every formula in context with WitPrep's SAT Math Practice. Adaptive questions that test your formula application, not just memorization.

Key Takeaways

• The SAT reference sheet provides basic geometry formulas, but the majority of formulas you need — algebra, quadratics, exponents, trigonometry — must be memorized
• Algebra and Advanced Math together account for 70% of SAT Math — prioritize quadratic formula, discriminant, slope formulas, and exponent rules
• You do not need to calculate standard deviation on the SAT, but you must understand what it measures and how to compare data sets
• The Desmos graphing calculator is a powerful tool but is not a substitute for formula knowledge — use it to verify, not to solve from scratch
• Focus your memorization on formulas you consistently miss in practice — not every formula on this list needs equal study time