Nth Root Calculator
Calculate the nth root of a number, such as a cube root or fourth root, for any positive whole-number degree.
Your results
Calculation breakdown
- Nth root
- x^(1/n)
Worked example
The cube root (n = 3) of -8 is -2, since -2 × -2 × -2 = -8.
Assumptions
- Odd-degree roots of negative numbers are real and calculated correctly.
- Even-degree roots of negative numbers return an error.
How this calculator works
This calculator finds the nth root of a number for any root degree you specify, such as the cube root (degree 3) or fourth root (degree 4). It handles negative numbers correctly for odd-degree roots.
Frequently asked questions
Can I find a cube root of a negative number?
Yes, odd-degree roots of negative numbers are real numbers, for example the cube root of -8 is -2.
What about even-degree roots of negative numbers?
Even-degree roots of negative numbers aren't real, so the calculator shows an error message in that case.
What if the root degree is zero?
A root degree of zero is undefined, so the calculator shows an error message.
Editorial review and responsibility
Reviewed by the CalcAussie editorial team on 21 September 2026. Review scope: Method, Australian terminology, material assumptions, source links and user-facing limitations.
Calculator results remain estimates based on the figures entered. Check material decisions against current official information and report a suspected error so it can be reproduced and corrected.