What should you program into your calculator for the SAT and ACT, and how?

As of November 2026: As of November 2026, the digital SAT has the Desmos graphing calculator built into Bluebook and requires removing programs with algebra functionality from a handheld, while the ACT allows the TI-84 and requires removing only programs with CAS functionality. So we program a TI-84 for the ACT and use Desmos on the SAT.

Use Desmos on the digital SAT, carry a programmed TI-84 on the ACT, and practice every tool on a timed mock before test day.

By Nick Standlea, Test Prep Gurus. Figures may be quoted with attribution to Test Prep Gurus.

Desmos is built into the digital SAT. Bluebook includes Desmos with graphing and scientific options. Handhelds that are graphing, scientific or 4-function are also allowed, with restrictions.

Programs on a TI-84 belong on the ACT. The ACT says TI-84 calculators are allowed, and only programs with CAS functionality must be removed. The SAT requires removing programs with algebra functionality.

Some models must stay home on the ACT. The ACT prohibits every model number beginning with TI-89 or TI-92, plus the HP Prime.

What does each test allow on its calculator?

These are the College Board's and the ACT's own words, quoted from their policy pages.

Rule	What it means	In their words	Source
Digital SAT: Desmos is built into Bluebook	Yes	Bluebook contains an embedded Desmos calculator with two optionsgraphing or scientific.	Source
Digital SAT: Desmos is available on the Math section	Yes, at any point	Students can toggle between scientific and graphing options at any point in the Math section.	Source
Digital SAT: students may bring an approved handheld	Allowed	You may use your own approved handheld calculator or take advantage of the Desmos calculator embedded in Bluebook.	Source
Digital SAT: handheld types allowed	Graphing, scientific and 4-function, with restrictions	Graphic, scientific, and 4-function calculators are allowed, subject to the restrictions below.	Source
Digital SAT: CAS calculators	Prohibited	Only non-CAS calculators may be used.	Source
Digital SAT: QWERTY keyboards	Prohibited	Calculators with QWERTY keyboards.	Source
Digital SAT: other equipment	Only battery-operated handheld equipment	Only battery-operated, handheld equipment can be used for testing.	Source
Digital SAT: programs with algebra functionality	Must be removed	You must remove programs that have algebra functionality	Source
Digital SAT: stored documents	Must be removed	You must remove any stored documents from your calculator.	Source
ACT: TI-84	Allowed	Yes, TI-84 calculators are allowed on the ACT	Source
ACT: TI-89 and TI-92 models	Prohibited	All model numbers beginning with TI-89 or TI-92	Source
ACT: TI-Nspire without CAS	Permitted	TI-Nspire (non-CAS) is permitted.	Source
ACT: HP Prime	Prohibited	Hewlett-Packard HP Prime	Source
ACT: CAS calculators	Prohibited	Calculators with built-in or downloaded computer algebra system (CAS) functionality are prohibited	Source
ACT: programs with CAS functionality	Must be removed; other programs may stay	Only programs that have CAS functionality must be removed.	Source
ACT: apps with CAS functionality	Must be removed	Apps that have CAS functionality must be removed as well.	Source
ACT: calculator on the math section	Allowed for any problem you choose	You may use your calculator for any problems you choose	Source

Rules can change. Read the current College Board and ACT calculator pages before each test day.

What do we program into a calculator, and what do we use on the digital SAT?

This is our own method at Test Prep Gurus. It does not come from the College Board or ACT.

Tool	Task	What to do	Why it helps
Desmos on the SAT	Solve an equation	Type the left side of the equation on one line and the right side on a second line. Tap the point where the two graphs cross and read its x value.	The crossing point is the answer, and you can see whether there is one solution, two or none.
Desmos on the SAT	Find zeros, the vertex and the intercepts	Type the function, then tap the points where the curve touches an axis or turns. Desmos shows each point's coordinates.	You read the answer from the picture instead of doing long algebra.
Desmos on the SAT	Solve a system of equations	Type both equations on separate lines and tap the point where the two graphs meet.	The shared point is the solution to the system.
Desmos on the SAT	Fit a line or curve to data	Make a table of x and y pairs, then type a regression line such as y1~mx1+b so Desmos finds the best fit.	You get the slope and intercept of the best-fit line without computing them by hand.
Desmos on the SAT	Check an answer choice	Put the value from the answer choice in place of the variable and see if both sides match.	It is a quick way to test four choices when the algebra is slow.
Desmos on the SAT	Find a mean or median	Enter the numbers as a list and use the mean() or median() function on that list.	It saves time and avoids adding mistakes on statistics questions.
Desmos on the SAT	See what values satisfy a condition	Replace a constant with a slider and drag it to see which values make the condition true.	You can see how the answer changes instead of guessing.
TI-84 on the ACT	Find both roots of a quadratic	Store a short program that asks for a, b and c and prints both roots from the quadratic formula. This is our own practice, not an ACT recommendation.	It gives both answers in seconds and removes sign errors.
TI-84 on the ACT	Find distance and midpoint	Store a short program that asks for two points and prints the distance and the midpoint.	Coordinate geometry questions become a matter of typing in two points.
TI-84 on the SAT and ACT	Solve an equation with the graph	Type each side of the equation into Y= as Y1 and Y2, graph them, then use the intersect routine under 2nd TRACE to find where they cross.	You find the solution without rearranging the equation.
TI-84 on the SAT and ACT	Test values	Type the expression into Y= and open the table under 2nd GRAPH to see its value at many inputs.	You can test answer choices or look for a pattern fast.
TI-84 on the SAT and ACT	Line of best fit	Enter the data in STAT, then use LinReg to get the line of best fit.	You get the slope and intercept of the trend line in a few steps.
Any handheld	Practice and check	Practice every program on a full mock test before test day, and confirm the program does not add a prohibited feature.	A tool you have never timed can cost you more than it saves.

Nick Standlea reviews every row. The quadratic and distance programs are for the ACT only.

What should you program into your calculator for the SAT and ACT?

For the ACT, we program a TI-84 with a quadratic-formula program and a distance-and-midpoint program; for the digital SAT, we skip programs and use the Desmos calculator built into Bluebook.

The reason is the rules. For a handheld on the SAT, the College Board says, "You must remove programs that have algebra functionality." The ACT says, "Only programs that have CAS functionality must be removed." Those lines are not the same, so a calculator can be ready for the ACT and not ready for the SAT.

The Desmos graphing calculator is built into Bluebook, the app for the digital SAT. That means programs matter most on the ACT and for students who would rather hold a calculator in their hands. Rules can change, so we tell families to read the current College Board and ACT calculator pages before each test.

What does each test allow on its calculator?

The digital SAT allows graphing, scientific and 4-function handheld calculators with restrictions, and the ACT allows the TI-84 but prohibits every model beginning with TI-89 or TI-92.

Both tests ban CAS calculators. CAS means a computer algebra system, the kind of calculator that can do algebra with letters for you. The ACT says TI-84 calculators are allowed. On the ACT, the HP Prime is prohibited, while the TI-Nspire without CAS is permitted.

The SAT adds more rules for handhelds. Calculators with QWERTY keyboards are not allowed, only battery-operated handheld equipment can be used, and any stored documents must be removed. On the ACT math section, your student may use a calculator for any problems they choose.

What should we use on the digital SAT?

On the digital SAT, we use Desmos, which Bluebook offers in graphing and scientific modes that students can switch between at any point in the Math section.

Our students use it for most of the slow algebra. To solve an equation, type the left side on its own line and the right side on the next line, then tap where the graphs cross and read the x value. For a system, type both equations and tap the point they share. For zeros, a vertex or intercepts, type the function and tap where the curve touches an axis or turns.

Desmos also handles data. Enter the numbers as a list and use mean() or median(). Make a table of x and y pairs and type a regression line so Desmos finds the best fit. Replace a constant with a slider and drag it to see which values work. To check an answer choice, put its value in for the variable and see if both sides match.

A student who prefers a handheld may still bring an approved one to the SAT. Our rule is simple: on the SAT, the handheld carries no algebra programs, and Desmos does the heavy lifting.

What should we program into a TI-84, and how?

On a TI-84, we store a quadratic-formula program and a distance-and-midpoint program, and we use them on the ACT only.

The quadratic program asks for a, b and c and prints both roots from the quadratic formula. It gives both answers fast and removes sign errors. The distance-and-midpoint program asks for the coordinates of the points and prints the distance and the midpoint, so coordinate geometry turns into typing. This is our own practice, not an ACT recommendation.

We keep the quadratic-formula program for the ACT because the College Board says programs with algebra functionality must be removed from a handheld on the SAT. We treat the distance program the same way, and we delete both before an SAT.

Some TI-84 tools need no program at all, and we teach them for both tests. To solve an equation, type each side into Y=, graph them, and use the intersect routine under 2nd TRACE. To test values, open the table under 2nd GRAPH. For a line of best fit, enter the data in STAT and use LinReg. Our rule is that a student should be able to explain every line of any program they carry.

What should we not bring?

The ACT prohibits every model beginning with TI-89 or TI-92, the HP Prime, and any calculator with CAS functionality.

On the ACT, programs and apps with CAS functionality must be removed, and other programs may stay. On the SAT, CAS calculators and calculators with QWERTY keyboards are not allowed. Programs with algebra functionality and stored documents must be removed, and only battery-operated handheld equipment can be used.

We tell families to check the calculator at home before each test. Put in fresh batteries, keep only the programs that fit that test, and clear anything extra from memory.

How do we practice it?

We practice every program and every Desmos move on a full mock test before test day.

A tool you have never timed can cost you more than it saves. On a timed mock, a student learns which questions go faster on Desmos or the TI-84 and which go faster by hand. We also confirm that each program does not add a prohibited feature.

Practice with the exact calculator your student will carry on test day. For the SAT, that means practicing with Desmos on full digital mock tests, so the screen feels familiar.

What should we do this month?

Book a free mock SAT and a free mock ACT with Test Prep Gurus by calling 949.229.5359 or visiting https://www.prepgurus.com/take-the-next-step.

The mock results show which test fits your student and which calculator habits need work. We tell families to plan 6 to 12 weeks of prep before a test date that counts. Our students prepare for the whole test every sitting, not only the math.

Before each test day, open the current calculator page for that test and check your student's calculator against it.

Questions parents ask

Is Desmos built into the digital SAT?
The Desmos graphing calculator is built into Bluebook, the app for the digital SAT.

Can my child use a quadratic formula program on the SAT?
We keep the quadratic-formula program for the ACT because the College Board says programs with algebra functionality must be removed from a handheld on the SAT.

Is the TI-84 allowed on the ACT?
The ACT says TI-84 calculators are allowed.

Which calculators are prohibited on the ACT?
The ACT prohibits every model beginning with TI-89 or TI-92, the HP Prime, and any calculator with CAS functionality.

How long should my child prep before a real test?
We tell families to plan 6 to 12 weeks of prep before a test date that counts.

Ready to plan the next test date? Free mock SAT and free mock ACT at Test Prep Gurus, then a plan built on the result: prepgurus.com/take-the-next-step or 949.229.5359.

Method and sources: The calculator rules quote the College Board's SAT calculator policy page and the ACT's calculator policy page, CAS FAQ, calculator video page and Preparing for the ACT guide, as they stood in November 2026. The programs and Desmos steps are Test Prep Gurus' own practice, reviewed by Nick Standlea, and do not come from the College Board or ACT. This page holds no score bands or prices. Policies can change, and the current pages from each testing organization govern on test day.