How it works
Calculate the square root of a number, or its cube root, or any nth root, with the domain rules enforced.
Enter a number and choose the root: square (√), cube (∛), or an nth root with a degree from 2 to 100. The calculator returns the requested root and also shows the square and cube roots when they are real numbers. Negative inputs are allowed for odd roots; square roots and even roots of negative numbers are rejected instead of returning an error value.
Formula
√x = x^(1/2); ∛x = x^(1/3); nth root = x^(1/n). For negative x, odd roots use sign(x) × |x|^(1/n).
x- Number to take the root of (number)
n- Root degree for nth roots (2–100)
Examples
- Square root of 144Number 144 · square root12
- Cube root of −27Number −27 · cube root−3
- 4th root of 81Number 81 · nth root · degree 43
Frequently asked questions
Which roots can I calculate?
Square, cube and any whole-number degree from 2 to 100. The square and cube roots are also shown alongside the requested root when they are real.
Why is a negative square root rejected?
No real number squared gives a negative result. Odd roots of negative numbers are defined, so cube roots and odd nth roots are allowed.
How to read the result
The principal root is returned: non-negative for even degrees, and negative for odd roots of negative numbers.
Limitations
Real roots only; complex roots are not shown. Results are rounded to eight decimals.
Source: Standard radical and power definitions.