Completing the Square Calculator

Complete squares step by step

The calculator will try to complete the square for the given quadratic expression, ellipse, hyperbola, or any polynomial expression, with steps shown.

Enter an expression:

If the calculator did not compute something or you have identified an error, or you have a suggestion/feedback, please write it in the comments below.

Introducing the Complete the Square Calculator—your optimal solution for effortlessly tackling quadratic expressions. Our specialized tool doesn't just present the answer; it guides you through the entire process, ensuring you grasp the underlying techniques.

How to Use the Completing the Square Calculator?

  • Input

    Start by entering your expression.

  • Calculation

    Once you've entered your expression, click the "Calculate" button.

  • Result

    The calculator will quickly display the expression in its appropriate form. For those keen on understanding the process, the tool provides a comprehensive breakdown detailing each step taken to achieve the result.

What Is Meant by Completing the Square?

Completing the square is an important technique tailored to address quadratic expressions. This technique changes an expression by transforming it into the sum of a perfect square and some residue. This simplifies its further analysis.

What Core Formula Is Used in the Completing the Square Method?

Suppose you're given a standard quadratic polynomial of the following form:


Completing the square aims to rewrite it into the following form:


where $$$h=-\frac{b}{2a}$$$ and $$$k=c-\frac{b^2}{4a}$$$.

Detailed steps:

  • If the coefficient near $$$x^2$$$ is not $$$1$$$, factor it out from the terms containing $$$x$$$:

  • Add and Subtract the Square of Half the Coefficient Near $$$x$$$:

  • Rewrite:

  • Rewrite as the Square of a Binomial:


From this form, you can easily determine the vertex of the parabola the expression represents and further solve for $$$x$$$ using various methods.

Why Choose Our Completing the Square Calculator?

  • Precision and Accuracy

    Our calculator is equipped with advanced algorithms, ensuring that every solution you get is both accurate and correct.

  • User-Friendly Interface

    With an intuitive design, our tool caters to both students and professionals. Whether you're a beginner or an advanced user, navigating the calculator is a breeze.

  • Step-by-Step Explanations

    Not only does the calculator provide the answer, but it also offers a detailed step-by-step breakdown of the solution process. This is an invaluable feature for those aiming to understand the intricacies of the "completing the square" method.

  • Immediate Results

    Time is of the essence. Our calculator processes expressions instantly, delivering quick results, and saving you time, especially during exam revisions or problem-solving sessions.


Who can benefit from this calculator?

Anyone dealing with quadratic expressions, whether they be students, teachers, or professionals, can benefit from this calculator. It's particularly helpful for those wanting to understand the process behind completing the square.

How accurate is the calculator?

Our Completing the Square Calculator is very accurate. It uses reliable algorithms to ensure correct results.

Does this calculator solve quadratic equations?

No, this particular calculator focuses on the "completing the square" method. However, there are tools designed for that specific task.

How do I handle coefficients that are fractions or decimals?

The calculator is designed to process expressions with both fractional and decimal coefficients. Simply input them as they are and the calculator will do the rest.