Cube Root Calculator
Find the cube root of any number, including negative values.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Cube Root Calculator
Enter any number and the cube root appears instantly. Results update as you type with no buttons needed.
- Enter a number. Type any positive or negative number, including decimals.
- Read the result. The cube root is displayed along with whether the result is exact (a perfect cube) or approximate.
- Copy or share. Use the buttons to copy the result or share a pre-filled link.
About Cube Roots
The cube root of a number x is the value that, when multiplied by itself three times, gives x. For example, the cube root of 27 is 3, because 3 x 3 x 3 = 27. Unlike square roots, cube roots work with negative numbers: the cube root of -8 is -2, because (-2) x (-2) x (-2) = -8.
Perfect cubes include 1, 8, 27, 64, 125, 216, 343, 512, 729, and 1000. Most numbers do not have exact cube roots. All calculations run in your browser with no data sent to any server.
Frequently Asked Questions
Can you take the cube root of a negative number?
Yes. Unlike square roots, cube roots of negative numbers are real. The cube root of -27 is -3, because (-3) x (-3) x (-3) = -27.
What is a perfect cube?
A perfect cube is a number whose cube root is a whole number. Examples include 1, 8, 27, 64, 125, 216, 343, 512, 729, and 1000.
How is cube root related to exponents?
The cube root of x is the same as x raised to the power of 1/3. So cbrt(8) = 8^(1/3) = 2. You can use the exponent calculator with 1/3 (0.333333) to get the same result.