Synthetic Division Calculator

Divide a polynomial by a linear factor x − r using synthetic division, and read off the quotient and remainder.

Quotient
Remainder

How to Do Synthetic Division

Enter the polynomial coefficients and the root r of the divisor x − r.

1

Enter the coefficients

List every coefficient from the highest power down to the constant, including zeros for any missing terms — for example 1, 0, −4 for x² − 4.

2

Enter the divisor

Synthetic division divides by a linear factor x − r. Enter r; to divide by x + 1, use r = −1.

3

Read the quotient and remainder

The quotient is one degree lower than the input. A remainder of 0 means x − r is a factor.

Frequently Asked Questions

What is synthetic division?
Synthetic division is a shortcut for dividing a polynomial by a linear factor x − r using only the coefficients, with no x symbols written down. It gives the same quotient and remainder as polynomial long division in far fewer steps. Dividing x³ − 6x² + 11x − 6 by x − 1 gives the quotient x² − 5x + 6 with a remainder of 0. It only works for a linear divisor, so anything of higher degree needs long division.
How do I divide by x + 1?
In synthetic division, write the divisor as x − r. Since x + 1 = x − (−1), use r = −1. The calculator handles the sign for you.
What does the remainder tell me?
By the remainder theorem, the remainder equals the polynomial evaluated at r. So dividing by x − 1 and getting a remainder of 0 tells you that P(1) = 0. A zero remainder therefore means r is a root and x − r is a factor, which is the factor theorem. A non-zero remainder still gives you P(r) for free: dividing x³ − 6x² + 11x − 6 by x − 2 leaves 0, while dividing by x − 4 leaves 6.
Is my data sent anywhere?
Nothing you enter into the synthetic division calculator leaves your device. The synthetic division calculator does all of its arithmetic client-side in JavaScript, so your coefficients and divisor are never uploaded to a server. No account is needed and no calculation is stored or logged. Once the page has loaded it works with no network connection at all.