Math · FREE ONLINE TOOL

Root Calculator

Find square roots, cube roots and other integer-index roots, including supported real odd roots of negative numbers.

Your inputs

Calculations run in your browser. No account needed.

EXAMPLE RESULTCalculated locally
Root
3
Clear inputs. Transparent methods.
My workspace

Calculate with your inputs to save a result or compare scenarios.

How it works

A useful distinction

A principal root is one answer

The square-root result for 9 is 3, while the equation x² = 9 has two real solutions, 3 and −3. Use the root result as a function value, not as a complete equation solution list.

Understanding the root index and input value

The root index specifies which power would reproduce the entered value. A square root and a cube root therefore answer different questions about the same number. Review the real-number restrictions when the input is negative or the index is not a whole number. The calculator's root result should not be confused with listing every possible solution of a polynomial equation.

Nth root: formula and assumptions

Nth root = value ^ (1/n).

Negative values have real odd roots; even roots of negative values are complex and outside this mode.

Worked example

Using the Nth root example:

Inputs
Number
27
Root degree
3
Method

Nth root = value ^ (1/n).

Result

Example result

Root: 3

These are illustrative inputs. Change the values to explore a different scenario.

Formula references

References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.

Common questions

Can a negative number have a real root?

It has real odd roots, such as the cube root of −8 being −2. Even roots of negative values are not real.

Does the calculator list every complex root?

No. This mode returns the supported real root rather than the full set of complex roots.

Prepared by Finflo. See our methodology and editorial policy.