Quadratic Formula Calculator

Solve a quadratic equation in the form ax² + bx + c = 0.

How to use the Quadratic Formula Calculator

Enter the coefficients a, b, and c. The calculator uses the quadratic formula and reports real or complex roots. Enter the known values, choose any required mode or unit, and calculate the result. Review the labels and units before relying on the answer.

What this calculator does

Solve a quadratic equation in the form ax² + bx + c = 0. It is intended to make the calculation transparent and repeatable: you provide the known values, the calculator applies the relevant relationship, and the result is shown with the units or labels used by the tool.

When this tool is useful

Use the Quadratic Formula Calculator when you need a quick, repeatable check and already have the inputs requested by the page. It is useful for comparing scenarios, checking hand calculations, planning a task, or understanding how changing one input affects the result.

How the calculation works

For ax² + bx + c = 0, the roots are found from x = (−b ± √(b² − 4ac)) ÷ 2a.

Practical example

For example, enter coefficients a, b, and c from a quadratic equation to see the real or complex roots returned by the formula.

Things to keep in mind

  • Check units and input labels before calculating.
  • Keep enough decimal precision during the calculation and round the final answer to a level appropriate for your use.
  • Use the result as a practical aid and verify it against authoritative requirements when precision has legal, safety, financial, or professional consequences.