Negative values
Odd roots of negative numbers have real answers, such as the cube root of -8. Even roots of negative numbers require complex numbers, which this page does not display.
Example
The square root of 81 is 9 because 9 x 9 = 81. The cube root of -8 is -2 because -2 x -2 x -2 = -8.
Common mistakes
Do not enter 0 as the root degree. Also remember that even roots of negative values are not real-number results.
Limitations
This calculator returns real roots only. It does not display complex roots, symbolic simplification or exact radical forms.
Last reviewed: 2026-05-17