Free SAT tool

Desmos for the Digital SAT

The digital SAT includes a built-in Desmos calculator inside College Board's Bluebook app, with graphing and scientific modes available on both Math modules. Learn how it works, practice with the same calculator used on test day, and see technique-by-technique guidance below.

Open Desmos in Bluebook, or practice it right here on this page.
Learn the technique library A to Z below, matched to real questions.
Practice on real Digital SAT questions in the question bank.

Try the practice calculator Watch the 7-minute guide

A. Getting started

Everything below assumes you already know the calculator exists. Here is how to actually use it on test day and while you practice.

Open it in Bluebook

During both Math modules, a calculator icon opens the built-in Desmos tool in a side panel next to the question, so you never leave the test screen to use it.

Graphing vs. scientific

The built-in tool includes a toggle between a full graphing calculator and a simpler scientific calculator; switch between them as many times as you need during the section.

Handheld calculators are still allowed

College Board's calculator policy also allows an approved handheld calculator alongside the built-in one, if you prefer to bring your own. See College Board's calculator policy for the full list of approved models.

Type directly

Type expressions with your keyboard instead of clicking each symbol; the calculator accepts standard math notation and formats it as you go, which is faster once you're used to it.

B. Practice calculator

Loads Desmos's own testing calculator, the same interface built into Bluebook, in an embedded frame.

Calculator by Desmos. The Test Advantage is not affiliated with Desmos or College Board.

C. Technique library A-Z

Eleven ways to use Desmos on SAT Math, each with when to use it, three steps, and the mistake that trips most students up.

Check answer choices by graphing them

When to use it: Use this when a question gives you an equation and four answer choices, and solving by hand would take several algebra steps.

Type the given equation into the calculator as one expression.
Enter each answer choice as a second expression or as a point.
The choice that matches the graph, or makes the two sides equal, is correct.

Common mistake: Typing an answer choice with a sign or exponent error, which throws off the comparison even when your approach is right.

Find mean and median from a data set

When to use it: Use this when a question lists several numeric values and asks for the mean, median, or how one changes when a value is added or removed.

Enter the values into a Desmos table, one per row.
Use the calculator to sum the column and divide by the count for the mean.
Sort the values by eye in the table to identify the median.

Common mistake: Forgetting to re-sort after adding a new value, which gives the wrong median even though the mean is still correct.

Fit a line or curve to a table of points

When to use it: Use this when a question gives you a table of x and y values and asks for a line or curve of best fit, or a missing value that follows the same pattern.

Open a table and enter each x, y pair from the question.
Type a regression expression such as y1 ~ a x1 + b beneath the table.
Read the computed a and b values, or trace the fitted curve for the missing point.

Common mistake: Choosing a linear regression for data that is clearly curved, which gives a fitted line that does not match any of the answer choices.

Watch: Digital SAT Math - Desmos Lesson #9 Regression Read: SAT Regression on Desmos: Practice Problems, Solved

Graph a circle from its equation

When to use it: Use this when a question gives a circle equation and asks for the center, radius, or a point that lies on or inside the circle.

Type the equation exactly as given, including any negative signs inside the squared terms.
Let the calculator graph the circle automatically.
Trace the graph to read the center and radius, or check whether a given point falls on the circle.

Common mistake: Misreading the center's sign from the equation (x - h)^2 + (y - k)^2 = r^2, entering h or k with the wrong sign.

Watch: Digital SAT Math - Desmos Lesson #11 Equation of a Circle Read: SAT Circle Equations on Desmos: Tangent Slope and Arcs

Model exponential growth and decay

When to use it: Use this when a question describes a quantity that grows or shrinks by a percent each period, such as population, interest, or decay.

Write the exponential expression using the given starting value and rate.
Graph it and add a point at the time value the question asks about.
Read the y-value at that point, or trace to find when the quantity reaches a target value.

Common mistake: Using a growth rate as a whole number (5) instead of the multiplier (1.05), which produces a graph miles off from the real function.

Read a quadratic's vertex and zeros

When to use it: Use this when a question asks for a maximum, minimum, or where a quadratic crosses the x-axis, including quadratic word problems.

Type the quadratic expression into the calculator.
Let Desmos plot the parabola, then click the vertex point it labels automatically.
Click each x-intercept the same way to read the zeros directly.

Common mistake: Reading the vertex coordinates in the wrong order and reporting the y-value as the maximum x-value, or vice versa.

Watch: The BEST Way to Solve SAT Quadratic Word Problems

Shade a system of inequalities

When to use it: Use this when a question gives two or more inequalities and asks which point, or which answer choice, satisfies all of them.

Enter each inequality using the calculator's < , > , ≤, or ≥ symbols.
Desmos automatically shades the solution region for each one.
Look for the overlapping shaded area, or test each answer choice as a point to see if it falls inside it.

Common mistake: Entering a strict inequality (< or >) when the question uses ≤ or ≥, which shows a dashed boundary instead of a solid one and can hide a boundary point that should count.

Watch: Digital SAT Math - Desmos Lesson #5 Inequalities Read: SAT Inequalities on Desmos: Graph the Solution Set

Solve a single-variable equation fast

When to use it: Use this when a question asks you to solve directly for one variable and the algebra would take multiple steps by hand.

Type the full equation into the calculator exactly as written.
Desmos treats it as an equation and plots where it is true.
Click the marked point on the x-axis to read the solution value.

Common mistake: Leaving off a denominator or parenthesis when typing the equation, which changes the equation Desmos actually solves.

Watch: Digital SAT Math - Desmos Lesson #15 Solve Most Equations...FAST

Solve a system by graphing

When to use it: Use this when a question gives two equations and asks for the point, points, or values where both are true at once.

Enter the first equation as y1= and the second as y2= (or in their given form).
Let Desmos plot both and mark their intersection point automatically.
Click the intersection point to read its coordinates as the system's solution.

Common mistake: Graphing only one of the two equations and reading an intercept instead of the actual intersection point of both graphs.

Watch: Digital SAT Math - Desmos Lesson #2 Systems of Equations

Test constants with a slider

When to use it: Use this when a question asks what value of a constant, such as a or k, makes an equation true under a stated condition.

Type the equation with the unknown constant left as a letter.
Click the constant when Desmos offers to add a slider for it.
Drag the slider while watching the graph until the stated condition is met, then read the constant's value.

Common mistake: Leaving the slider step size too coarse, which skips past the exact value the question is asking for.

Watch: Easily Solve SAT Constants Questions

Work percent problems with a table

When to use it: Use this when a question involves a percent increase, decrease, or comparison across several values.

Enter the original values in one table column and the percent change as an expression in the next.
Let Desmos compute each new value automatically.
Compare the computed values to the answer choices instead of recalculating each one by hand.

Common mistake: Adding the percent as a whole number instead of converting it to a decimal multiplier first, which off-scales every computed value.

Read: How to Do Ratios and Percentages on Desmos

D. When not to use Desmos

Desmos is a tool, not a shortcut for every question. These three situations usually cost more time than they save.

Time traps

If a question can be answered with one or two lines of mental math or simple algebra, typing it into the calculator and reading a graph often takes longer than just solving it.

Format traps

Questions that ask you to identify a specific form of an equation (such as which expression is equivalent, in a required form) usually need algebraic reasoning about structure, not a graph.

Multi-constant problems

When a question has more than one unknown constant with no numeric relationship given between them, a single slider will not narrow the answer; work out the relationship algebraically first, then check it in Desmos.

E. Printable cheat sheet

Desmos on the SAT: quick reference

Technique	When to use it	Common mistake
Check answer choices by graphing them	Use this when a question gives you an equation and four answer choices, and solving by hand would take several algebra steps.	Typing an answer choice with a sign or exponent error, which throws off the comparison even when your approach is right.
Find mean and median from a data set	Use this when a question lists several numeric values and asks for the mean, median, or how one changes when a value is added or removed.	Forgetting to re-sort after adding a new value, which gives the wrong median even though the mean is still correct.
Fit a line or curve to a table of points	Use this when a question gives you a table of x and y values and asks for a line or curve of best fit, or a missing value that follows the same pattern.	Choosing a linear regression for data that is clearly curved, which gives a fitted line that does not match any of the answer choices.
Graph a circle from its equation	Use this when a question gives a circle equation and asks for the center, radius, or a point that lies on or inside the circle.	Misreading the center's sign from the equation (x - h)^2 + (y - k)^2 = r^2, entering h or k with the wrong sign.
Model exponential growth and decay	Use this when a question describes a quantity that grows or shrinks by a percent each period, such as population, interest, or decay.	Using a growth rate as a whole number (5) instead of the multiplier (1.05), which produces a graph miles off from the real function.
Read a quadratic's vertex and zeros	Use this when a question asks for a maximum, minimum, or where a quadratic crosses the x-axis, including quadratic word problems.	Reading the vertex coordinates in the wrong order and reporting the y-value as the maximum x-value, or vice versa.
Shade a system of inequalities	Use this when a question gives two or more inequalities and asks which point, or which answer choice, satisfies all of them.	Entering a strict inequality (< or >) when the question uses ≤ or ≥, which shows a dashed boundary instead of a solid one and can hide a boundary point that should count.
Solve a single-variable equation fast	Use this when a question asks you to solve directly for one variable and the algebra would take multiple steps by hand.	Leaving off a denominator or parenthesis when typing the equation, which changes the equation Desmos actually solves.
Solve a system by graphing	Use this when a question gives two equations and asks for the point, points, or values where both are true at once.	Graphing only one of the two equations and reading an intercept instead of the actual intersection point of both graphs.
Test constants with a slider	Use this when a question asks what value of a constant, such as a or k, makes an equation true under a stated condition.	Leaving the slider step size too coarse, which skips past the exact value the question is asking for.
Work percent problems with a table	Use this when a question involves a percent increase, decrease, or comparison across several values.	Adding the percent as a whole number instead of converting it to a decimal multiplier first, which off-scales every computed value.

F. Curated video playlist

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Topic lessons

Deep dives

Hardest questions

G. TTA blog library

Desmos SAT Practice Problems, With Answers

Nine October 2026 bank SAT Math questions to solve on Desmos: systems, sliders, quadratics, regression and cir...

When Should You Not Use Desmos on SAT Math?

When not to use Desmos on SAT math: College Board's own advice, six signs to work by hand, 3 bank questions to...

How to Do Ratios and Percentages on Desmos

Ratios on Desmos are divisions; percents are decimals or the % key. Moves for ratio tables, proportions and pe...

How to Solve for x on Desmos (SAT Method)

Solve for x on Desmos in 4 steps: graph each side, click where they cross, read the x-value. Three methods, tr...

Is Desmos Allowed on the SAT? Version, History and Where to Find It

Yes, Desmos is allowed on the SAT. See College Board's 2026-27 calculator policy, the SAT version of Desmos, w...

Desmos Guide: Complete Guide, Practice Plan, and Resources

Desmos for the Digital SAT: the three core tactics (regression, sliders, graphing systems), a 4-week practice...

Desmos Scientific vs Graphing on the SAT: When to Switch

Use Desmos graphing on the SAT for tables, graphs and systems, and the scientific calculator for fraction answ...

Desmos College Board Version: Open the SAT Graphing Calculator

Yes, the SAT has Desmos built into Bluebook for all of Math. Open the College Board version, see how it differ...

SAT Volume and Surface Area on Desmos: Cylinders, Cones

Type the volume formula into Desmos and let it do the arithmetic. Worked pipe, cone, sphere and tank examples,...

SAT Circle Equations on Desmos: Tangent Slope and Arcs

A tangent meets the radius at a right angle, so its slope is the negative reciprocal of the radius slope. Work...

SAT Trig Expressions on Desmos: Check Sin and Cos

Check SAT sin and cos expressions on Desmos: match the angle mode, store a test angle in a letter, and compare...

SAT Trig Expressions with Desmos: Simplify sin/cos Problems Without Identities

Most SAT trig problems look harder than they are. This guide shows you how to use the built-in Desmos calculat...

Unit Circle on Desmos: SAT Radian Problems Solved

Check unit-circle values on Desmos with cos and sin, find co-terminal angles with mod, and work SAT-style radi...

SAT Parallel Lines and Angles: Check on Desmos

When a line crosses two parallel lines, some angle pairs are equal and others add to 180. Learn which, then so...

SAT Trig Ratios on Desmos: Sin, Cos, Tan Examples

Write sin, cos or tan from the triangle first, then use Desmos for the square roots and trig values. Three SAT...

SAT Word Problems on Desmos: Graph It First

Write each quantity in one variable, graph both on Desmos, and read where they cross. Five SAT-style word prob...

SAT Regression on Desmos: Practice Problems, Solved

Five SAT regression problems solved on Desmos. Type the model with a tilde, pick linear, quadratic or exponent...

SAT Inequalities on Desmos: Graph the Solution Set

Type an inequality into Desmos and it shades the solutions. SAT-style systems, absolute value and quadratic in...

SAT Rate of Change on Desmos: Linear Functions, Solved

Put the points in a Desmos table and type y_1 ~ mx_1 + b to get the slope and intercept. Four SAT-style rate o...

SAT Absolute Value Equations and Inequalities on Desmos

Solve SAT absolute value equations on Desmos: graph both sides and click the crossings. Worked examples, V gra...

H. Practice next

SAT question bank Practice Math questions from real Digital SAT question banks. Build a study plan Turn today's score goal into a week-by-week plan. Digital SAT score calculator See what a raw score converts to on the 1600 scale.

I. Frequently asked questions

Does the digital SAT have a built-in calculator?

Yes. The digital SAT, taken through College Board's Bluebook app, includes a built-in Desmos calculator with both graphing and scientific modes, available on both Math modules of the test.

Can I use my own calculator instead of Desmos on the SAT?

Yes, College Board also allows an approved handheld calculator (non-CAS graphing or scientific) if you prefer it. You can toggle to the built-in Desmos calculator at any point during the Math section even if you bring your own.

Where can I practice with the same Desmos calculator used on the SAT?

Desmos publishes a testing version of its calculator that matches the one built into Bluebook, so you can practice with the same interface before test day rather than a different Desmos version. This page embeds it directly below.

Can I switch between the graphing and scientific calculator during the test?

Yes. College Board's calculator policy lets you toggle between the built-in graphing and scientific Desmos calculator at any point during the Math modules, as many times as you need.

Is there a printable Desmos cheat sheet for the SAT?

Yes. This page includes a printable cheat sheet summarizing the technique library above; use the "Print cheat sheet" button in that section to print just the summary.

Source: College Board's calculator policy, https://satsuite.collegeboard.org/in-school-assessments/calculator-policy, and Desmos's own testing calculator, https://www.desmos.com/testing/collegeboard/graphing. The Test Advantage is not affiliated with College Board or Desmos.