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Polynomial Factoring Calculator

Factor a polynomial up to degree 12 over the integers: takes out the GCF, finds rational roots and quadratic or cubic factors, and lists every root.

Use ^ for powers (x^2) or type x². Products and brackets such as 3x(x+1)(x-2) are fine. One variable only.

Enter a polynomial in one variable and this solver searches for a product of factors with whole-number or fraction coefficients. It takes out the greatest common factor, searches for rational roots, and can also find higher-degree factors, such as x⁴ + 4 = (x² + 2x + 2)(x² - 2x + 2). Each factor is listed with its multiplicity and roots.

How to use this tool

  1. Type the polynomial, for example 6x^2 + x - 2 or 2x^3 - 8x. Products such as (x+1)(x^2-4) are expanded first.
  2. Check the "Expanded polynomial" line to confirm the input was read the way you meant.
  3. Read the factored form; a repeated factor is shown with a power.
  4. The table gives the roots of each factor: exact fractions or surds when available, with numerical approximations otherwise.

Formula

P(x) = c · xᵏ · f₁(x)^m₁ · f₂(x)^m₂ · …

c is the constant factor (the GCF of the coefficients, with the sign), k is the power of x, and each fᵢ is a verified factor with integer coefficients and multiplicity mᵢ. Rational roots p/q obey the rational root theorem: p divides the constant term and q divides the leading coefficient. A quadratic factor whose discriminant b² − 4ac is not a perfect square has irrational or complex roots and stays as it is. Every factor is confirmed by exact integer division before it is shown.

Example

x³ - 6x² + 11x - 6: the possible rational roots are ±1, ±2, ±3 and ±6. P(1) = 1 − 6 + 11 − 6 = 0, P(2) = 8 − 24 + 22 − 6 = 0 and P(3) = 27 − 54 + 33 − 6 = 0, so the answer is (x - 1)(x - 2)(x - 3) with roots 1, 2 and 3.

Frequently asked questions

What does "irreducible" mean here?

A factor is irreducible over the rationals when it cannot be written as a product of lower-degree polynomials with rational coefficients. x² + 1 and x² − 2 are both irreducible, even though x² − 2 = (x − √2)(x + √2) over the real numbers.

Can it factor non-monic quadratics like 6x² + x − 2?

Yes. It returns (3x + 2)(2x - 1): the rational roots −2/3 and 1/2 become the factors 3x + 2 and 2x − 1.

Does it handle differences of squares and sums of cubes?

Yes, they are ordinary factorisations: x⁴ − 16 = (x + 2)(x − 2)(x² + 4) and x³ + 8 = (x + 2)(x² − 2x + 4).

Can I use two variables?

No — this tool factors polynomials in one variable. Expressions such as x² − y² need multivariate factoring.

Last updated: 2026-10-30

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