Root Calculator

Find the square root, cube root, or any nth root of a number, including odd roots of negative numbers. Calculates in your browser.

2 for square root, 3 for cube root, and so on.

Result

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Expression-

Show the math

The nth root is the same as raising to the power 1/n:

ⁿ√x = x^(1/n)

A root undoes a power, so the cube root of 27 is 3 because 3³ = 27. Even roots of negative numbers have no real value, while odd roots of negatives do, the cube root of −8 is −2. All math runs locally in your browser.

What this does

A root calculator finds the nth root of a number, the value that, raised to the power n, gives your number. It covers the square root, the cube root, and any higher root.

How to use it

  1. Enter the number.
  2. Enter the root degree (2 for square root, 3 for cube root).
  3. Read the result.

How it works

The nth root is the same as raising to the power 1/n. Even roots (square, fourth) need a non-negative input, but odd roots (cube, fifth) work for negatives too, since a negative times itself an odd number of times stays negative.

ⁿ√x = x^(1/n)

Understanding your result

A root undoes a power: the cube root of 27 is 3 because 3³ = 27. Even roots of negative numbers have no real value, because nothing squared is negative, while odd roots of negatives do, the cube root of −8 is −2. The bigger the root degree, the closer the result moves toward 1.

Example

The square root of 16 is 4, the cube root of 27 is 3, and the cube root of −8 is −2.

Sources & methodology

Last updated .

Frequently asked questions

Can you take the root of a negative number?

Only odd roots (cube, fifth, …) of negatives have a real answer, the cube root of −8 is −2. Even roots of negatives are not real numbers.

What is the nth root?

It is the value that, multiplied by itself n times, gives your number. It equals raising the number to the power 1/n.

How is a root related to an exponent?

A root is a fractional exponent: the nth root of x is x^(1/n). The square root is x^(1/2).

Is my data stored?

No. Everything is calculated locally in your browser.