About the Cubic Equation Calculator
Solve cubic equations ax³ + bx² + cx + d = 0 for all three roots (real and complex) with the discriminant.
Also known as: cubic solver, third degree equation, solve cubic, cubic roots.
How to use this calculator
- Enter a, b, c, d.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Cubic Equation formula
Δ = 18abcd − 4b³d + b²c² − 4ac³ − 27a²d²
Worked example
Using the values pre-filled in the calculator above:
- a = 1
- b = -6
- c = 11
- d = -6
the calculator returns:
- Roots: 1, 2, 3
- Discriminant Δ: 4
- Real roots: 3
- Factored form: (x - 1)(x - 2)(x - 3)