SAT Math Formulas — What You Must Memorize (And What You Don't)

The biggest scoring leak in SAT Math isn't knowledge — it's assuming the reference sheet covers more than it does. It gives you exactly 11 formulas (geometry and volume); the other 14 that decide Module 2 scores live in your memory. Here's the complete must-memorize list with firing conditions.

Quick answer: Given on test: circle, triangle, rectangle area, Pythagorean theorem, 30-60-90 & 45-45-90 ratios, four volume formulas. Must memorize: slope, point-slope, slope-intercept, quadratic formula, percent change, average=sum/n, exponential growth, vertex x=−b/2a, SOHCAHTOA, radians, sin²+cos²=1, function substitution.

Lines and linear relationships

The most-tested family on the whole test. Slope m = (y₂−y₁)/(x₂−x₁); point-slope y − y₁ = m(x − x₁) when you know one point; slope-intercept y = mx + b for reading what a line means in context. The trap: in word problems, m and b have units — '2500 + 120t' means $2,500 up front and $120 per month; questions ask what 120 means, not what the total is. Also know parallel (equal slopes) vs perpendicular (negative reciprocal) cold.

Quadratics

Three forms, three uses: standard ax² + bx + c for plugging into the quadratic formula x = (−b ± √(b²−4ac)) / 2a; factored form for zeros; vertex form a(x−h)² + k for reading the max/min directly. When you only need the vertex x, skip the formula: x = −b/2a. The trap: the discriminant b²−4ac counts real solutions — positive = two, zero = one, negative = none; questions ask 'how many real solutions' and reward computing only the discriminant.

Growth, averages and percent change

Exponential growth/decay: A = P(1 + r)^t (decay = (1 − r)); identify the growth factor per period and what t counts. Average: mean = sum/n — the SAT's favorite manipulation is giving you the average and count and asking for the missing value, so rearrange to sum = mean × n without hesitation. Percent change: (new − original)/original — the denominator is always the ORIGINAL, and a 20% increase followed by a 20% decrease does not return to start (0.8 × 1.2 = 0.96).

Trigonometry and circles

SOHCAHTOA covers right triangles: sin = opposite/hypotenuse, cos = adjacent/hypotenuse, tan = opposite/adjacent. Complementary angle fact: sin θ = cos(90° − θ) — tested directly. Radians: multiply degrees by π/180. The Pythagorean identity sin²θ + cos²θ = 1 appears in the harder Module 2 items, usually disguised as 'if sin θ = 3/5, what is cos θ' (answer: ±4/5 depending on quadrant). Circle questions lean on the given formulas plus the circle equation (x−h)² + (y−k)² = r², which is worth memorizing even though some forms provide it.

What the reference sheet does cover

So you never scroll for it again: circle area A = πr² and circumference C = 2πr, triangle area A = ½bh, rectangle A = lw, Pythagorean theorem, 45-45-90 (x : x : x√2) and 30-60-90 (x : x√3 : 2x) side ratios, and volumes of box (lwh), cylinder (πr²h), cone (⅓πr²h) and sphere ((4/3)πr³). Eleven formulas, visible in-module. Drill the other fourteen with the interactive sheet and its print view.

What SatCalcs doesn't do

We don't teach full lessons here — each formula gets its firing condition and trap, not a course
We don't include formulas outside the SAT's scope (no calculus, no matrices) to keep the memorize list honest

Frequently Asked Questions

Do you get a formula sheet on the Digital SAT?

Yes, but only geometry and volume — 11 formulas (areas, Pythagorean theorem, special right triangles, four volumes). No algebra, no quadratic formula, no trig identities. The test design assumes those are memorized, which is why the memorize list here matters more than the given list.

What math formulas should I memorize for the SAT?

The 14: slope, point-slope, slope-intercept, quadratic formula, discriminant logic, vertex x = −b/2a, percent change, average = sum/n, exponential growth/decay, SOHCAHTOA, sin θ = cos(90°−θ), radians↔degrees, sin²θ + cos²θ = 1, and the circle equation (x−h)² + (y−k)² = r². That set covers nearly every 'I blanked on the formula' moment in Module 2.

Is the quadratic formula given on the SAT?

No — it's the most famous omission from the reference sheet. Memorize x = (−b ± √(b²−4ac))/2a and practice writing it from memory at the start of every Math module until it's automatic.

Does the SAT test calculus or matrices?

No — SAT Math tops out at algebra II, geometry, trigonometry and basic statistics (mean/median/range, data interpretation). No calculus, no matrices, no formal proofs. If you're studying beyond that for the SAT, you're studying for a different exam.

How should I practice formulas so they stick?

Two passes: understand (one example per formula, like the hints in our sheet) then drill retrieval — blank page, write all 14 from memory, check, repeat every other day for two weeks. Recognition (seeing the formula) never survives test pressure; retrieval does. The printable sheet exists for the door-frame check.

More tools used in this guide

SAT Formula Sheet

Every formula the Digital SAT expects — official reference sheet items plus the algebra you must memorize — organized, with a print view.

SAT Score Calculator

Enter correct answers per module (or per paper section) — get section scores, your total, and the honest range around them.

More guides

SAT Score Chart

The Digital SAT raw-to-scaled chart (with ranges), percentile anchors, and the ACT concordance — one page, three tables.

How SAT Scoring Works

From raw answers to the 400–1600 report: adaptive modules, equating, Score Choice and superscoring, explained in order.