Quadratic Formula Calculator

Solve any quadratic equation of the form ax² + bx + c = 0. Enter the coefficients a, b, and c to find both roots (real or complex), the discriminant, and a step-by-step solution.

Solve ax² + bx + c = 0
x = (−b ± √(b² − 4ac)) / 2a

About the Quadratic Formula

The quadratic formula solves any quadratic equation ax² + bx + c = 0:

The discriminant (b² − 4ac) tells you about the roots:

  • > 0: Two distinct real roots
  • = 0: One repeated real root (double root)
  • < 0: Two complex (imaginary) roots

Frequently Asked Questions

If a = 0, the equation is linear (bx + c = 0), not quadratic. The solution is simply x = −c/b.

When the discriminant is negative, the roots involve the square root of a negative number. These are written as complex numbers with a real part and an imaginary part (e.g., 2 + 3i).

About the Quadratic Formula Calculator

This free quadratic formula calculator helps you get accurate results instantly without needing to work through the math manually. Whether you need a quick estimate or a precise figure, having a reliable tool on hand saves time and reduces errors compared to manual calculation.

How to Use This Calculator

  1. Enter your values in the input fields above. Each field is labeled to guide you.
  2. Double-check your inputs — results are only as accurate as the numbers you enter.
  3. Click the Calculate button to see your result instantly.
  4. Use the result for your planning, budgeting, or decision-making.

Why Accurate Calculations Matter

Small errors in math calculations can compound into significant problems. A 1% miscalculation in a budget or measurement can translate to hundreds or thousands of dollars in wasted resources, or result in having to redo work entirely. This calculator uses the standard formulas and methods to give you reliable results you can trust.

Tips for Getting the Best Results

Frequently Asked Questions

Is this calculator free? Yes — completely free with no account, login, or payment required. Use it as many times as you need.

How accurate are the results? This calculator uses the standard formulas for quadratic formula calculations. Results are accurate for typical use cases. For specialized or high-stakes applications, consult a professional.

Does it work on mobile? Yes. This calculator is fully responsive and works on smartphones, tablets, and desktops.