How to use the Cube Root Calculator
Enter any number, including negatives and decimals. You get the cube root as a decimal and, when the number is not a perfect cube, a simplified radical form.
What a cube root is
The cube root of a number is the value that, multiplied by itself three times, gives that number. The cube root of 27 is 3 because 3 × 3 × 3 = 27. Unlike square roots, cube roots of negative numbers are ordinary real numbers: the cube root of −8 is −2.
Simplifying and real uses
To simplify, pull out the largest perfect cube. 54 is 27 × 2, so its cube root is 3∛2. Cube roots also turn volumes back into lengths. A cube shaped box that holds 64 litres, which is 64,000 cubic centimetres, has sides of ∛64,000 = 40 cm.
How it works
∛n
Examples
- Cube root of 54
∛54 = 3.77976315 Simplified: 3∛2
- Cube root of 27
∛27 = 3 Perfect cube.
- Cube root of 1000
∛1,000 = 10 Perfect cube.
Limitations and assumptions
Computed in your browser with standard double-precision arithmetic unless the page says otherwise. Very large or very small values may be rounded.
Frequently asked questions
What is a cube root?
The number that, multiplied by itself three times, gives the original: ∛27 = 3.
Can negative numbers have cube roots?
Yes. ∛(−8) = −2, unlike square roots.
How do I simplify a cube root?
Pull out perfect cube factors: ∛54 = ∛(27 × 2) = 3∛2.
How is it related to volume?
The edge of a cube is the cube root of its volume.