Can You Use a Calculator on the SAT, ACT, GRE & MCAT?

Yes, you can use a calculator on the SAT and ACT — but only on the math sections and only with approved devices. The GRE provides a basic on-screen calculator you must use. The MCAT bans calculators entirely. Each exam has strict rules, and breaking them can get you dismissed or your scores canceled. One detail most students miss: the College Board banned CAS (Computer Algebra System) calculators starting August 2025, meaning popular models like the TI-Nspire CX II CAS are now prohibited. Knowing these policies before test day can protect your score and save months of preparation from going to waste.

What Is a Standardized Test Calculator Policy?

A standardized test calculator policy is a set of rules from the testing organization that defines which devices students can and cannot use during an exam. These rules exist to keep the test fair for every student worldwide.

The four major exams — SAT, ACT, GRE, and MCAT — each have different policies. Some allow personal handheld devices. Others provide a built-in digital tool. One bans all calculating devices completely. Understanding these differences is critical because a device that works perfectly on one exam may get you disqualified from another.

The organizations behind these rules include the College Board (SAT), ACT Inc. (ACT), ETS — Educational Testing Service (GRE), and the AAMC — Association of American Medical Colleges (MCAT).

How Calculator Policies Work Across All Four Exams

Each testing body sets its own rules. Here is a side-by-side breakdown of what is and is not allowed.

Expert insight: Many students prepare with a CAS graphing calculator in high school, then discover on test day it is banned. Always verify your specific model against the testing organization's prohibited list at least two weeks before the exam.

The SAT digital test through the Bluebook app includes an embedded Desmos graphing calculator that every student can access — even those who bring their own device. This means you effectively have two tools available: your handheld and the Desmos tool.

The ACT also now offers a Desmos graphing calculator within its online testing platform for state and district tests. For paper-based ACT tests, students must bring their own approved device.

The GRE gives every test-taker an identical basic on-screen calculator with addition, subtraction, multiplication, division, and square root functions. You cannot bring any external device.

The MCAT provides no calculator at all. The AAMC designs questions so they can be solved with mental math, estimation, and scratch work on a provided noteboard booklet.

Calculator Rules — Key Facts and Figures

SAT (College Board):

• Calculators are permitted only during Math modules
• As of August 2025, all CAS calculators are prohibited
• Students must remove stored programs with algebra functionality
• Prohibited models include: HP Prime, TI-Nspire CX II CAS, Casio CFX-9970G
• Sharing calculators during the test is not allowed

ACT (ACT Inc.):

• Calculators are permitted only during the Mathematics test
• CAS calculators with built-in or downloaded functionality are banned
• Infrared data ports must be covered with opaque tape
• Paper tape must be removed and sound must be turned off
• The TI-Nspire (non-CAS version) is permitted

GRE (ETS):

• An on-screen calculator is available only during Quantitative Reasoning
• The calculator is identical whether testing at a center or at home
• No personal calculators of any kind are allowed inside the testing room
• Attempting to bring one may result in disqualification

MCAT (AAMC):

• No calculators are permitted — zero exceptions
• No electronic devices of any kind are allowed in the testing room
• Students receive a reusable noteboard booklet and marker for scratch work
• All MCAT math is designed to be solvable through estimation and mental arithmetic

⚠️ NOTE: A common misconception is that disabling CAS mode on a CAS calculator makes it acceptable. This is false for both the SAT and ACT. If the model has CAS capability, it is banned regardless of its current settings.

Key Factors to Consider

• Know your exam's specific rules. The SAT and ACT allow personal calculators. The GRE provides one. The MCAT bans them. Mixing up policies can cost you your test score.
• Practice with your exact test-day device. Using a new or unfamiliar calculator on test day wastes valuable time. Spend at least 4-6 weeks using the same model during all practice sessions.
• Verify your calculator model against the banned list. Calculator policies can change annually. The College Board's 2025 CAS ban caught many students off guard. Check the official website within two weeks of your test date.
• Learn the on-screen tool if it applies. For the digital SAT, digital ACT, and GRE, practicing with the built-in tool is just as important as studying content. The Desmos testing version has different features than the classroom version.
• Build mental math skills regardless of your exam. Even on tests that allow calculators, reaching for a device on every question slows you down. Strong estimation skills help on all four exams.
• Bring backup batteries or a backup calculator. Test centers will not provide a replacement if your device fails. A dead calculator means testing without one.

Common Mistakes People Make

1. Bringing a CAS calculator to the SAT or ACT. Many students use a TI-Nspire CX II CAS throughout high school without realizing it is now banned. If your model name includes "CAS," it will be confiscated. Switch to a TI-84 Plus CE or Casio fx-9750GIII instead.

⚠️ WARNING: Getting caught with a prohibited device can result in dismissal from the exam and cancellation of all scores — not just the math section.

2. Never practicing with the Desmos or on-screen calculator. Students who rely entirely on their handheld miss out on Desmos features that can solve problems faster, such as graphing systems of equations. Spend time with the tool at desmos.com/testing before test day.

3. Assuming the GRE calculator handles complex functions. The GRE's on-screen calculator is extremely basic. It has no memory, no parentheses grouping (in older versions), and no trigonometric functions. Overreliance on it leads to wasted time and errors.

4. Ignoring mental math preparation for the MCAT. Students who prepare for the MCAT using a calculator during study sessions build a dangerous dependency. Practice all physics and chemistry problems by hand from day one of your preparation.

5. Forgetting to clear stored programs before the exam. Both the SAT and ACT require students to delete all programs with algebra functionality from their calculators. Proctors can check your device. Failing to clear programs is treated as a policy violation.

Practical Tips

Use an online calculator during early study sessions, then switch to your test-day device. An online calculator helps you check work quickly when learning new concepts. As your test date approaches, transition fully to the device you will actually use.

Practice the "no-calculator challenge" once a week. Set aside one practice session where you solve math problems without any device. This builds speed and confidence for questions where reaching for a calculator actually wastes time.

Set your calculator to degree mode, not radians. Trigonometry problems on the SAT and ACT use degrees. A calculator set to radians will give wrong answers on every trig question, and most students never check this setting.

Label your calculator with your name. Test centers are crowded. If your calculator falls off the desk or gets mixed up during a break, a label helps you recover it quickly.

For the MCAT, memorize key math shortcuts. Learn to estimate logarithms using the formula log(a × b) = log(a) + log(b). Master common square roots, and practice converting between fractions and decimals. These skills save 30-60 seconds per question.

Take at least one full-length practice test under real conditions. Use only the tools your actual exam allows. This means Desmos-only for the digital SAT, the ETS on-screen tool for the GRE, and zero devices for the MCAT.

Your Next Step

Knowing each exam's calculator policy is one of the simplest ways to protect your test score. Check your device against the official approved list, practice under real test conditions, and build mental math skills as a safety net. Start by reviewing the specific policy page for your upcoming exam today — a few minutes of preparation now can prevent a disaster on test day.