ACT® Calculator Policy: Guidance for Your Students

As a secondary educator, one of your key responsibilities is preparing students for standardized tests like the ACT®. A critical aspect of this preparation is ensuring students understand calculator policies, as using an unauthorized device—or failing to use a calculator effectively—can impact their performance.

With the shift to both paper-based and digital ACT® formats, it’s essential to clarify:

• Which calculators are allowed (and which are not)
• How calculator rules differ between test formats
• How to successfully use the Desmos calculator on the digital ACT®
• Strategies to help students maximize their calculator use

ACT® Calculator Policy: What’s Allowed and What’s Not

The ACT® allows calculators for the mathematics test (including ACT WorkKeys® Applied Math), but all questions can be solved without one. Students should use calculators to save time rather than rely on them completely.

Permitted Calculators

Students may use any four-function, scientific, or graphing calculator, as long as it is not on the prohibited list and any required modifications have been made​.

• Basic four-function calculators (addition, subtraction, multiplication, division)
• Scientific calculators (advanced math functions, exponents, logarithms, etc.)
• Graphing calculators without CAS functionality

Prohibited Calculators

Students cannot use:

Calculators with Computer Algebra System (CAS) functionality, including:

• Texas Instruments: TI-89, TI-92, TI-Nspire CAS
• Hewlett-Packard: HP Prime, HP 48GII, HP 40G, HP 49G, HP 50G
• Casio: fx-CP400 (ClassPad 400), ClassPad 300, ClassPad 330, Algebra fx 2.0, CFX-9970G

Other prohibited devices:

• Calculators built into phones, tablets, or smartwatches
• Devices with QWERTY keyboards
• Handheld, laptop, or tablet computers
• Calculators with internet access or Bluetooth connectivity
• Electronic writing pads or pen-input devices (except Sharp EL 9600)

Special Rules for Certain Calculators

Some graphing calculators can be used if modified, meaning:

• Remove all stored documents or programs with CAS functionality
• Cover infrared ports with opaque tape (for specific HP models)
• Turn off sound if the calculator makes noise
• Remove power cords

For a complete list of approved and prohibited calculators, visit the ACT®’s official policy page​.

ACT® Paper vs. Digital: How the Rules Differ

With more schools administering the digital ACT®, students need to prepare for a built-in calculator experience instead of bringing their own device. However, while Desmos is provided, students can still bring an approved, handheld calculator.

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How to Use the Desmos Calculator on the Digital ACT®

The Desmos Graphing Calculator is the default calculator for digital ACT® testing (State & District, and PreACT Online Suite)​. While the Desmos calculator is widely used in classrooms, the ACT® version has limitations.

Differences Between Desmos for ACT® vs. Standard Desmos

Disabled on the ACT® version:

• Images, folders, and notes
• Advanced trig and stats functions (e.g., sec, cot, arcsec, mad, cov)
• Audio capabilities

Enabled:

• Graphing functions
• Scientific calculator features
• Default degree angle mode (instead of radians)

To ensure students are using the correct version, direct them to Desmos Testing​.

Tips to Help Students Avoid Calculator Mistakes

Even with a calculator, students can lose points due to avoidable errors. Here are some best practices to teach them:

BEFORE Test Day

• Verify that their calculator is allowed and modify it if needed.
• If using Desmos, practice on the testing version to avoid confusion.
• Use the same calculator they’re comfortable with—test day is not the time to learn a new device.

DURING the Test

• Use the calculator strategically—some problems are faster to solve by hand.
• Check battery levels before the test (and bring a backup for paper-based testing).
• Don’t store notes in the calculator—this is considered a testing violation.
• Know how to quickly access functions—wasting time searching for buttons can cost points.

Next Steps: Get Your Students ACT®-Ready!

• Share this guide with students and families so they understand the calculator rules.
• Encourage students to practice with Desmos before test day.
• Explore Horizon Education’s ACT® prep tools to provide structured, data-driven practice.

By preparing students with the right tools and strategies, you’ll help them avoid test-day stress and maximize their ACT® math scores! Learn more about our ACT® prep solutions at Horizon Education.