ACT Math Section: Essential Formulas

The ACT (American College Testing) is a standardized test widely used for college admissions in the United States. Among its various sections, the ACT Math section holds significant weight, evaluating your mathematical skills and problem-solving abilities. Success in this section can positively impact your overall ACT score, potentially opening doors to your dream colleges and scholarships. To excel in the ACT Math section, you not only need to know the essential formulas but also employ comprehensive strategies for tackling the diverse range of math problems presented. In this comprehensive guide, we will provide you with a thorough list of essential math formulas, along with detailed strategies to help you achieve a high score on the ACT Math section.

Essential Math Formulas

Before delving into the strategies for the ACT Math section, let's ensure you have a solid grasp of the essential math formulas you'll need:

Arithmetic Formulas

1. Order of Operations (PEMDAS):

   - Parentheses

   - Exponents

   - Multiplication and Division (left to right)

   - Addition and Subtraction (left to right)

2. Percentages:

   - Percentage = (Part / Whole) × 100

   - To find a percentage of a number, multiply the number by the percentage.

3. Ratios and Proportions:

   - Ratio = (Part 1 / Part 2)

   - Proportion: (a / b) = (c / d)

Algebra Formulas

4. Linear Equations:

   - y = mx + b (slope-intercept form)

   - m = (change in y) / (change in x)

5. Quadratic Equations:

   - Quadratic Formula: x = (-b ± √(b² - 4ac)) / (2a)

6. Exponents:

   - xⁿ × xᵐ = x^(n + m)

   - (xⁿ)ᵐ = x^(n * m)

   - x⁻ⁿ = 1 / xⁿ

7. Logarithms:

   - logₐ(b) = c if and only if aᶿ = b

Geometry Formulas

8. Area and Perimeter:

   - Rectangle: Area = length × width, Perimeter = 2(length + width)

   - Triangle: Area = (base × height) / 2

   - Circle: Area = πr², Circumference = 2πr

9. Pythagorean Theorem:

   - a² + b² = c² (for a right triangle with sides a, b, and hypotenuse c)

10. Volume and Surface Area:

    - Rectangular Prism: Volume = length × width × height, Surface Area = 2lw + 2lh + 2wh

    - Cylinder: Volume = πr²h, Surface Area = 2πr² + 2πrh

11. Special Right Triangles:

    - 45-45-90 Triangle: Legs are congruent, hypotenuse = √2 times a leg.

    - 30-60-90 Triangle: Short leg = (1/2) × hypotenuse, long leg = √3 times short leg.

Trigonometry Formulas

12. Sine, Cosine, and Tangent

    - SOH-CAH-TOA:

      - sin(θ) = opposite / hypotenuse

      - cos(θ) = adjacent / hypotenuse

      - tan(θ) = opposite / adjacent

13. Reciprocal Trig Functions:

    - csc(θ) = 1 / sin(θ)

    - sec(θ) = 1 / cos(θ)

    - cot(θ) = 1 / tan(θ)

14. Trig Identities:

    - sin²(θ) + cos²(θ) = 1

    - 1 + tan²(θ) = sec²(θ)

    - 1 + cot²(θ) = csc²(θ)

Coordinate Geometry Formulas

15. Distance Formula:

    - Distance between two points (x₁, y₁) and (x₂, y₂): 

      - d = √((x₂ - x₁)² + (y₂ - y₁)²)

16. Slope Formula:

    - Slope (m) between two points: 

      - m = (y₂ - y₁) / (x₂ - x₁)

17. Midpoint Formula:

    - Midpoint between two points (x₁, y₁) and (x₂, y₂): 

      - (x, y) = ((x₁ + x₂) / 2, (y₁ + y₂) / 2)

Probability and Statistics Formulas

18. Probability:

    - Probability of an event A: P(A) = (Number of favorable outcomes) / (Total number of outcomes)

19. Mean (Average):

    - Mean = (Sum of all values) / (Number of values)

20. Median:

    - The middle value when values are arranged in ascending order.

21. Mode:

    - The most frequently occurring value in a set of data.

These formulas are fundamental for solving various types of math problems on the ACT Math section. Having a solid understanding of these formulas and knowing when and how to apply them is essential for success.

ACT Math Section Strategies

Now that you're armed with the essential math formulas, let's delve into comprehensive strategies for tackling the ACT Math section effectively:

1. Understand the Question Types

The ACT Math section consists of various question types, including algebra, geometry, trigonometry, and statistics. Familiarize yourself with the types of questions you'll encounter and understand the specific skills required for each question type.

2. Manage Your Time Wisely

Time management is critical on the ACT Math section. You have 60 minutes to answer 60 questions, which means you have an average of one minute per question. Don't get stuck on challenging questions; move on and return to them later if necessary.

3. Read Each Question Carefully

Take the time to read each question carefully. Pay attention to details, units, and any diagrams or graphs provided. Misreading a question can lead to incorrect answers.

4. Use Your Calculator Strategically

While a calculator is allowed on the ACT Math section, it's important to use it strategically. Don't rely solely on your calculator; use it as a tool to verify calculations and save time on lengthy computations

5. Practice Mental Math

Improve your mental math skills to solve problems more quickly and efficiently. This can be particularly helpful for questions that involve simple calculations.

6. Plug In Answer Choices

For some questions, especially algebraic and equation-solving problems, you can use the "plugging in" method. Substitute answer choices to see which one satisfies the equation or condition given in the question.

7. Draw Diagrams and Illustrations

For geometry and coordinate geometry questions, draw diagrams or illustrations on your scratch paper. Visualizing the problem can often lead to quicker solutions.

8. Simplify and Approximate

When dealing with complex expressions or calculations, look for opportunities to simplify or approximate. This can save time and reduce the chance of errors.

9. Eliminate Wrong Answer Choices

If you're unsure about an answer, try to eliminate obviously wrong answer choices. This increases your chances of guessing correctly.

10. Practice, Practice, Practice

Practice is key to improving your ACT Math skills. Use official ACT practice materials, take full-length practice tests, and review your mistakes to identify areas for improvement.

11. Review Formulas Regularly

Keep the essential math formulas handy and review them regularly. Being familiar with the formulas will save you time and reduce the chances of forgetting key concepts during the exam.

12. Simulate Test Conditions

When practicing, simulate actual test conditions as closely as possible. Take timed practice tests to get a feel for the pacing and pressure of the real exam.

13. Seek Additional Help if Needed

If you're struggling with specific math topics or concepts, consider seeking additional help from a teacher, tutor, or online resources. Don't hesitate to ask questions and seek clarification.

14. Stay Calm and Confident

Maintain a positive and confident mindset during the test. Stress and anxiety can negatively impact your performance. Remember that you have prepared thoroughly, and you are capable of tackling the math section successfully.


The ACT Math section is a significant component of the ACT exam, and a strong performance can enhance your overall ACT score, making you a more competitive college applicant. By mastering the essential math formulas and employing the comprehensive strategies outlined in this guide, you can approach the ACT Math section with confidence. Remember that consistent practice, effective time management, and a clear understanding of question types are key to your success. With dedication and preparation, you can achieve a high score on the ACT Math section and move closer to your college and career goals. Good luck!