What's on the official Digital SAT reference panel
Bluebook gives you an in-app reference panel in both math modules. You can open it any time. Here's everything that's on it:
Area & circumference
| Area of a rectangle | A = l × w |
| Area of a triangle | A = ½ × b × h |
| Area of a circle | A = π r² |
| Circumference of a circle | C = 2π r |
Right triangles
| Pythagorean theorem | a² + b² = c² |
| 30–60–90 special right triangle (sides opposite 30°, 60°, 90°) | 1 : √3 : 2 |
| 45–45–90 special right triangle (legs : hypotenuse) | 1 : 1 : √2 |
Volumes
| Rectangular prism | V = l × w × h |
| Cylinder | V = π r² h |
| Sphere | V = (4/3) π r³ |
| Cone | V = (1/3) π r² h |
| Pyramid | V = (1/3) × base area × h |
Angle facts
| Sum of interior angles of a triangle | 180° |
| Sum of angles in a circle | 360° |
| Radians in a full circle | 2π |
Formulas you have to memorize (not on the reference panel)
Algebra, advanced math, statistics, and trig together make up roughly 70% of the Digital SAT Math section, and essentially none of it is on the in-app reference panel. Memorize the formulas below before test day.
Linear equations
| Slope formula | m = (y₂ − y₁) / (x₂ − x₁) |
| Slope-intercept form | y = mx + b |
| Point-slope form | y − y₁ = m(x − x₁) |
| Standard form | Ax + By = C |
| Parallel lines | Same slope (m₁ = m₂) |
| Perpendicular lines | Slopes multiply to −1 (m₁ × m₂ = −1) |
| Midpoint formula | ((x₁ + x₂) / 2, (y₁ + y₂) / 2) |
| Distance formula | √((x₂ − x₁)² + (y₂ − y₁)²) |
Quadratics & polynomials
| Quadratic formula | x = (−b ± √(b² − 4ac)) / 2a |
| Discriminant | b² − 4ac (> 0 → 2 real roots, = 0 → 1, < 0 → none) |
| Vertex form | y = a(x − h)² + k, vertex (h, k) |
| Factored form | y = a(x − r₁)(x − r₂), roots r₁ and r₂ |
| Difference of squares | a² − b² = (a + b)(a − b) |
| Perfect square trinomials | (a + b)² = a² + 2ab + b²; (a − b)² = a² − 2ab + b² |
| Sum and product of roots (ax² + bx + c) | Sum = −b/a; Product = c/a |
Exponents & radicals
| Product of powers | x^a × x^b = x^(a + b) |
| Quotient of powers | x^a / x^b = x^(a − b) |
| Power of a power | (x^a)^b = x^(ab) |
| Zero exponent | x⁰ = 1 (for x ≠ 0) |
| Negative exponent | x^(−a) = 1 / x^a |
| Fractional exponent | x^(1/n) = ⁿ√x |
| Rational exponent | x^(a/b) = (ᵇ√x)^a = ᵇ√(x^a) |
Circles in the xy-plane
| Equation of a circle (center (h, k), radius r) | (x − h)² + (y − k)² = r² |
| Arc length (θ in radians) | s = r θ |
| Area of a sector (θ in radians) | A = ½ r² θ |
Right-triangle trigonometry
| SOH-CAH-TOA | sin = opp/hyp, cos = adj/hyp, tan = opp/adj |
| Pythagorean identity | sin²θ + cos²θ = 1 |
| Co-function identities | sin(θ) = cos(90° − θ); cos(θ) = sin(90° − θ) |
| Tangent in terms of sin and cos | tan θ = sin θ / cos θ |
Statistics & data
| Mean | Sum of values / Number of values |
| Median | Middle value when ordered (average of the two middles if even count) |
| Range | Max − Min |
| Standard deviation | A measure of spread. Higher means data points are more spread from the mean |
| Probability | P(event) = favorable outcomes / total outcomes |
Percent change & ratios
| Percent change | (New − Old) / Old × 100% |
| Percent of a number | (percent / 100) × number |
| Simple interest | I = P × r × t |
| Compound interest | A = P (1 + r/n)^(n t) |
Functions
| Function composition | (f ∘ g)(x) = f(g(x)) |
| Exponential growth | y = a (1 + r)^t |
| Exponential decay | y = a (1 − r)^t |
| Function transformations | y = f(x − h) + k shifts h right, k up; y = a f(x) stretches vertically by a |
Why only 12 geometry formulas made the cut
The College Board's logic is sort of charming if you think about it. They picked formulas that are easy to forget under pressure but trivial to apply once you have them in front of you. Sphere volume? Nobody remembers (4/3)πr³ cold. Cone volume? Same deal. The numerical coefficients are weird. So those get a pass.
What they didn't include is anything that requires real conceptual work. The quadratic formula, for instance. That's arguably the single most-tested formula on the entire test, and it's nowhere on the panel. Same with the slope formula, the distance formula, exponent rules, the equation of a circle, anything trig beyond a 30-60-90 reminder, the discriminant, vertex form, percent change, standard deviation, average rate of change, function composition. None of it.
Why? Because the College Board considers those "content," not "reference." If you don't know that b² - 4ac tells you how many real roots a quadratic has, that's a learning gap, not a memory lapse. They're not going to bail you out.
The huge gap: 70% of Math isn't on the panel
Here's a stat that should change how you prep. Roughly 35% of the Digital SAT Math section is Algebra. Another 35% is Advanced Math (quadratics, exponentials, polynomials, rational expressions, function notation). That's 70% of your score, and almost none of those formulas live on the reference panel.
The rest splits between Problem Solving and Data Analysis (around 15%), and Geometry and Trigonometry (around 15%). The reference panel helps with maybe half of that bottom 15%. Do the math. The panel is a bandaid on a small cut while you're running a marathon.
So look at the must-memorize tables on this page. Algebra. Quadratics. Exponents. Circles. Trig. Stats. Percents. Functions. That's your real reference sheet. The College Board just won't print it for you.
Memorize the panel anyway. Yes, even though you can tap it.
Hot take: students who rely on tapping the reference panel during the test lose around 20 to 30 seconds per geometry question. That doesn't sound like much. On a 22-question, 35-minute module, it can be the difference between finishing and leaving three blank.
Cone volume is (1/3)πr²h. Sphere volume is (4/3)πr³. Pyramid volume is (1/3)lwh. Memorize them now and the tap becomes a confirmation, not a lookup. You glance, you nod, you move on.
The other reason to memorize: pattern recognition. When you know the volume of a cylinder cold (πr²h), and a question gives you a cone inscribed in a cylinder, you'll instantly see the cone is one-third the cylinder's volume. That's a 10-second problem if you know it, a 90-second problem if you're flipping back to the panel.
Mnemonics and memory tricks that actually stick
Some formulas resist memorization because they're abstract symbol salad. Mnemonics fix that. Here are the ones worth using:
- SOH-CAH-TOA. Sine = Opposite over Hypotenuse. Cosine = Adjacent over Hypotenuse. Tangent = Opposite over Adjacent. Burn this in. Trig questions appear on roughly every Digital SAT, and if you're fumbling with which ratio is which, you've already lost.
- FOIL. First, Outer, Inner, Last. The order of multiplication when you expand (a+b)(c+d). Works on every binomial product. Not flashy, but it's a checklist that prevents the "I forgot the middle term" mistake.
- "Negative b plus or minus the square root of b squared minus 4ac, all over 2a." Sing it. There's a famous version set to "Pop Goes the Weasel." Sounds dumb. Works.
- PEMDAS. You learned it in middle school. Don't forget it. The Digital SAT writes questions specifically to punish kids who do multiplication before parentheses.
- The discriminant rhyme. "If b squared minus 4ac is positive, two real roots. If zero, one real root. If negative, no real roots." Sing it twice, you have it forever.
Don't roll your eyes at mnemonics. The kids who score 780+ on Math use them. They're just quieter about it.
Common pitfalls, formula by formula
Algebra mistakes that wreck good students
The slope formula is (y₂ - y₁) / (x₂ - x₁). Students reverse it constantly. They'll put the x's on top, or they'll use point 1 in the numerator and point 2 in the denominator. The fix: pick a consistent order. Always do "second minus first" for both top and bottom. Pick one point as your "first" and stick with it through both calculations.
Distance formula? Same deal, but worse, because there's a square root. Students forget to square the differences before adding them. Or they add, then square, instead of squaring, adding, then square-rooting. Read the formula twice before you plug.
Quadratic formula sign errors
Negative b. That's the killer. If b in your equation is -7, then negative b is +7. Students see -7 and write -(-7) and somehow end up with -7 again. Write it down explicitly. If you have x² - 7x + 6 = 0, then a=1, b=-7, c=6. Negative b is 7. Then 7 plus or minus the square root of 49 minus 24, all over 2. Slow is fast here.
Exponent rule confusion
x² times x³ is x⁵, not x⁶. You add the exponents when multiplying same bases. You multiply them when raising a power to a power. Students mix these up under time pressure. Repeat after me: multiplying bases means adding exponents. Powers of powers means multiplying exponents. Tattoo it somewhere.
Also: x⁻² is 1/x², not -x². Negative exponents flip, they don't negate. And x⁰ equals 1 for any nonzero x. Not zero. One.
Circle equation mixups
The standard form is (x - h)² + (y - k)² = r². The center is (h, k), and the radius is r. Two traps. First, the signs flip. If the equation reads (x + 3)² + (y - 4)² = 25, the center is (-3, 4), not (3, -4). Second, the right side is r squared, not r. If you see 25 on the right, the radius is 5. If you see 16, the radius is 4. Students grab the number on the right and treat it as the radius. Don't.
When to fire up Desmos instead of a formula
The Digital SAT gives you a built-in Desmos graphing calculator. It's the same Desmos you've probably used in class. And it's overpowered for what the test asks.
Use Desmos when:
- You're solving a quadratic. Type it in. Click the x-intercepts. Done. No formula, no factoring, no completing the square. Just two clicks.
- You're finding the intersection of two lines or curves. Type both equations. Click the intersection point. Coordinates appear.
- You're solving a system of equations. Same as above. Two equations, two clicks.
- You forget a formula. If you can't remember the vertex of a parabola, just graph it and read the vertex off the screen.
- You're checking your work. Did you get x = 3 algebraically? Graph it. Confirm. Move on.
- The problem involves a function you don't recognize. Plot it. See what it looks like. Half the time you'll spot the answer visually.
When NOT to use Desmos
Desmos isn't always faster. Some traps:
- Simple linear stuff. If the problem is "solve 3x + 5 = 17," you'll lose 20 seconds typing it into Desmos vs. 5 seconds in your head. Be honest about when mental math wins.
- Exact integer answers. Desmos sometimes shows 2.9999999 when the answer is 3. Be ready to round or rationalize.
- Word problems that require setup first. Desmos can't read English. You still have to translate the words into equations. If the bottleneck is the setup, Desmos doesn't help.
- Algebraic manipulation questions. "Which of the following is equivalent to (x+3)(x-5)?" You can't click your way to that. Just expand it.
- Geometry with no coordinates. A triangle with given sides and angles? Desmos doesn't draw it for you. You need the formulas.
The compound interest trap
Compound interest shows up on the Digital SAT more often than you'd expect. The formula is A = P(1 + r/n)^(nt). P is principal, r is the annual rate as a decimal, n is the number of compounding periods per year, t is years.
The trap? The College Board likes to write the question so r and n look interchangeable. Example: "A bank account earns 6% annual interest, compounded quarterly. What expression gives the balance after t years?" Half the students write (1.06)^t. Wrong. Quarterly means n=4, so it's (1 + 0.06/4)^(4t), which is (1.015)^(4t).
If interest is compounded monthly, n=12. Compounded daily, n=365. Compounded continuously, you switch to A = Pe^(rt). Know all four.
Quadratic formula vs. factoring vs. completing the square: what to reach for first
You've got three tools for solving quadratics. Most students default to one and use it for everything. Bad strategy. Here's the order I'd teach:
- Desmos. Honestly. Type the equation, click the x-intercepts. If the answer is a clean integer or simple decimal, you're done in 10 seconds.
- Factoring. If the leading coefficient is 1 and the constant term has obvious factor pairs, try this. x² - 5x + 6 = 0 factors to (x-2)(x-3). Five seconds.
- Quadratic formula. When factoring doesn't work cleanly or you see ugly coefficients. It always works. Just slow.
- Completing the square. Rarely the fastest path for solving, but essential when the question asks you to convert to vertex form, or to find the vertex without graphing.
If a question literally says "write in vertex form," completing the square is your move. Otherwise, save it for last.
The triangle area pitfall
Triangle area is (1/2)bh. Base times height, divided by two. The classic mistake: using a slant side as the height when the triangle isn't a right triangle.
The height has to be perpendicular to the base. In an isoceles or scalene triangle, that means the height is an interior altitude, not one of the sides. If a question gives you three side lengths but no height, you can't just plug a side in. You'll need the Pythagorean theorem (or trig) to find the actual altitude first.
Pro move: if you're given two sides and the included angle, the area is (1/2)ab·sin(C). That's not on the reference panel, but it shows up enough that you should know it cold.
Paper to digital: the formula sheet didn't change
When the SAT went fully digital in March 2024, basically everything changed. Section structure. Adaptive difficulty. Reading passages got shorter. The Math section got a built-in Desmos calculator on every question (no more "no calculator" section).
But the reference panel? Identical. Same 12 formulas. Same layout, just in a slide-out drawer instead of printed at the start of the section. The College Board didn't add the quadratic formula, didn't add the slope formula, didn't throw you a bone on exponent rules. They kept it lean.
That tells you something. The College Board has had decades to add formulas to that sheet and they haven't. They want you to know the content. The panel is for the stuff that's easy to forget, not the stuff that's tested most.
Which formula categories show up most
Rough frequency, based on released Digital SAT practice tests and the official Bluebook practice exams:
- Linear equations and systems. Around 8 to 10 questions per test. Slope, slope-intercept, point-slope, parallel and perpendicular lines, systems with no solution or infinite solutions.
- Quadratics and polynomials. Around 6 to 8 questions. Factoring, the quadratic formula, vertex form, the discriminant, sum and product of roots.
- Exponential functions and exponent rules. Around 4 to 5 questions. Growth and decay, compound interest, simplifying expressions with rational exponents.
- Function notation and transformations. Around 3 to 4 questions. f(g(x)), shifts, reflections, evaluating from a table or graph.
- Geometry and right triangle trig. Around 4 to 6 questions. Circle equations, arc length, sector area, similar triangles, SOH-CAH-TOA.
- Statistics and data. Around 3 to 4 questions. Mean, median, standard deviation (conceptual, not calculation), margin of error, scatterplots.
- Percent and ratios. Around 2 to 3 questions. Percent change, percent of, unit conversions.
If you're short on prep time, weight your studying to match. Linear and quadratic content alone make up almost half the test.
Problems where the formula sheet is useless
Some questions don't reward formula knowledge at all. They reward reading comprehension and clean arithmetic.
- Linear word problems. "A plumber charges $50 plus $30 per hour. Write an equation." No formula. Just translation.
- Ratio and proportion setups. Cross-multiplication is a technique, not a formula. You either see it or you don't.
- Reading from graphs and tables. Pure data extraction. The formula sheet won't tell you what the y-axis is measured in.
- Probability with given counts. Favorable over total. Knowing the formula doesn't help if you can't count the favorable outcomes.
- Algebraic equivalence questions. "Which expression is equivalent to" whatever. You expand, factor, or simplify. There's no shortcut formula.
For these, the prep is repetition. Do enough practice problems and the patterns become automatic. Formulas can't save you on questions that test thinking, not recall.
How to actually use this page
Don't just scroll. Pick three formulas from the must-memorize tables that you're shaky on. Write them out by hand on a notecard. Do five practice problems using each one. Then come back tomorrow and do five more.
Recognition isn't recall. You can read the quadratic formula a hundred times and still freeze when a problem demands you produce it from memory. The only fix is using it on real problems until it's muscle memory.
And keep the reference panel in your back pocket. It's a safety net, not a strategy. The students who score 750+ on Digital SAT Math know every formula on this page cold and treat the panel as a sanity check, nothing more.
Frequently asked questions
Does the Digital SAT give you a formula sheet?
Yes. Bluebook includes a slide-out reference panel with 12 geometry formulas, available on every Math question. It covers basic area, volume, the Pythagorean theorem, and special right triangle relationships. It does not include algebra, quadratic, exponent, or trig formulas beyond the special triangles.
How many formulas are on the Digital SAT reference sheet?
Twelve. They're all geometry: circle area and circumference, rectangle area, triangle area, the Pythagorean theorem, 30-60-90 and 45-45-90 special triangles, and volumes of rectangular boxes, cylinders, spheres, cones, and pyramids. Plus three reminders about degrees in a circle, radians in a circle, and angles in a triangle.
Is the quadratic formula on the Digital SAT reference sheet?
No. The quadratic formula is one of the most-tested formulas on the entire Math section, but the College Board doesn't include it on the reference panel. You have to memorize it. The same goes for the slope formula, distance formula, exponent rules, and circle equations.
Do I need to memorize the formulas that are already on the reference panel?
Yes, even though you can tap to see them. Looking up a formula costs 20 to 30 seconds per question, and on a 35-minute module that adds up fast. Memorize the panel so you can use it as a confirmation, not a lookup.
Can Desmos replace memorizing formulas on the Digital SAT?
Partially. Desmos handles quadratics, systems, intersections, and graphing tasks beautifully. But it can't do algebraic manipulation, can't translate word problems, and can't help with proofs or equivalence questions. You still need to know the core formulas.
What formulas should I memorize beyond the Bluebook reference panel?
Top priorities: quadratic formula, discriminant, slope formula, point-slope and slope-intercept forms, distance and midpoint formulas, exponent rules, the equation of a circle in standard form, SOH-CAH-TOA, compound interest formula, percent change, and basic function transformations. These cover roughly 70% of Math section questions.
Has the Digital SAT formula sheet changed from the paper SAT?
No. The reference panel contains the same 12 geometry formulas that appeared on the paper SAT. The College Board kept the formula sheet identical when the test went fully digital in March 2024, even though the rest of the test changed significantly.
What percent of the Digital SAT Math is geometry?
Around 15%. Geometry and Trigonometry combined make up roughly 5 to 7 questions out of the 44 total Math questions. The rest is Algebra (about 35%), Advanced Math (about 35%), and Problem Solving and Data Analysis (about 15%).
Which formula trips up the most Digital SAT students?
The compound interest formula and exponent rules. Students commonly forget to divide the rate by n for non-annual compounding, and they confuse the rules for multiplying versus raising powers. The quadratic formula is also a frequent source of sign errors when b is negative.
Should I write down formulas on scratch paper at the start of the Math section?
Yes, if it helps you. Many top scorers jot down the quadratic formula, slope formula, and circle equation on their scratch paper before starting. It takes 30 seconds and removes the 'wait, what was that?' risk during the section.
Drill the formulas in real questions
Cheetah Prep's 15,000+ practice questions give every formula on this page a workout in real Digital SAT contexts, with step-by-step Desmos walkthroughs.
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