Cube Root Calculator
Find the real cube root of any positive, negative, or decimal number instantly.
About cube roots
Cube root examples
Perfect cubes return exact integers, while other inputs usually return rounded decimals.
| Number | Cube root | Explanation |
|---|---|---|
| 27 | 3 | Three cubed equals twenty-seven. |
| -64 | -4 | A negative number has a negative real cube root. |
| 2 | 1.2599210499 | The cube root is irrational and displayed as a decimal. |
| 0.001 | 0.1 | One tenth cubed equals one thousandth. |
How to find a cube root
- Enter the real number whose cube root you need.
- Select Calculate Cube Root to apply the real cube-root operation.
- Read the result and use the verification value to confirm that cubing it returns the input.
Frequently asked questions
Can a negative number have a cube root?
Yes, every negative real number has one negative real cube root. Cubing a negative value preserves its negative sign.
What is a perfect cube?
A perfect cube is the product of an integer multiplied by itself three times. Its cube root is therefore an integer.
Is a cube root the same as dividing by three?
No, a cube root reverses cubing rather than ordinary multiplication by three. Dividing 27 by three gives 9, while its cube root is 3.
Why is the answer rounded?
Many cube roots are irrational numbers with infinitely many nonrepeating digits. The calculator displays a rounded decimal that is convenient to read and use.
How does cube root relate to cube volume?
A cube volume equals its edge length cubed. Taking the cube root of the volume therefore recovers the edge length.