Here's the good news: the digital SAT hands you a formula sheet on every Math question. Here's the catch: it only covers geometry. Everything that actually decides your Algebra and Advanced Math score, you have to carry in your head. This is the exact shortlist.
What the SAT gives you (don't waste memory on these)
The Bluebook reference sheet is one tap away on every Math question. It includes the common geometry and volume formulas, so there's no point drilling them:
- Area of a circle: A = πr² · Circumference: C = 2πr
- Area of a rectangle: A = ℓw · Area of a triangle: A = ½bh
- Pythagorean theorem: c² = a² + b²
- Special right triangles: 30-60-90 (sides x, x√3, 2x) and 45-45-90 (sides s, s, s√2)
- Volumes: rectangular box ℓwh, cylinder πr²h, sphere ⁴⁄₃πr³, cone ⅓πr²h, pyramid ⅓ℓwh
- A circle has 360° (2π radians); a triangle's angles sum to 180°
The sheet is 100% geometry. There is no algebra on it — and algebra plus advanced math is about 70% of the section. So the list below, which the sheet doesn't give you, is where your memory should go.
What you must memorize
Lines & slope
- Slope: m = (y₂ − y₁) / (x₂ − x₁)
- Slope-intercept form: y = mx + b
- Point-slope form: y − y₁ = m(x − x₁)
- From standard form ax + by = c, the slope is −a/b
- Parallel lines share a slope; perpendicular slopes are negative reciprocals (m and −1/m)
Quadratics & advanced math
- Quadratic formula: x = (−b ± √(b² − 4ac)) / 2a
- The discriminant b² − 4ac tells you the number of real solutions (positive = 2, zero = 1, negative = 0)
- Vertex x-coordinate of a parabola: x = −b / 2a
- Sum of roots = −b/a; product of roots = c/a (huge time-savers on "sum/product of solutions" questions)
- Difference of squares: a² − b² = (a + b)(a − b)
Percent, growth & averages
- Percent change: (new − old) / old × 100
- Exponential growth: y = a(1 + r)ᵗ · decay: y = a(1 − r)ᵗ
- Average (mean): sum = average × number of values — memorize it in this form; SAT questions almost always give you the average and ask for the sum
- Probability: favorable outcomes / total outcomes
Coordinate geometry & circles
- Distance between two points: √((x₂ − x₁)² + (y₂ − y₁)²)
- Midpoint: ((x₁ + x₂)/2, (y₁ + y₂)/2)
- Equation of a circle: (x − h)² + (y − k)² = r², center (h, k), radius r
Right-triangle trig
- SOH-CAH-TOA: sin = opp/hyp, cos = adj/hyp, tan = opp/adj
- Co-function identity: sin(x°) = cos(90° − x°) — a favorite SAT trick
Don't just memorize formulas — memorize the trigger for each one. "Sum of the solutions" should instantly fire −b/a. "How much did it grow each year" should fire the exponential model. Formulas you can recite but can't recognize in a problem earn zero points. Our SAT Math playbook covers how to build that recognition.
Frequently asked questions
Does the digital SAT give you a formula sheet?
Yes — a reference sheet is built into Bluebook and available on every Math question, covering common geometry and volume formulas. It has no algebra, so those you must memorize.
What math formulas do I have to memorize?
The ones not on the sheet: slope and line forms, the quadratic formula and vertex, the circle equation, percent change, exponential growth/decay, averages, probability, distance and midpoint, and SOHCAHTOA.
Do I still need formulas if there's a calculator?
Yes. Desmos does the arithmetic, but you still need the formula to know what to compute and how to set the problem up.