Nth Root Calculator
Find the nth root of a number, such as a square root or cube root.
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ⁿ√x
ⁿ√x
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Square root
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Nth Root Calculator by TheCalcTools
How the Nth Root Calculator works
Enter the number and the root you want (2 for square root, 3 for cube root, and so on).
The calculator takes the absolute value to the power 1/n and restores the sign for odd roots.
The square root is shown for comparison.
The formula
ⁿ√x = x^(1/n)
Worked example
Using the default values shown in the calculator:
| Number (x) | 81 |
|---|---|
| Root (n) | 4 |
- We want the 4th root of 81.
- 81^(1/4) = 3.0000, because 3 × 3 × 3 × 3 = 81.
- For comparison, √81 = 9.00.
Result:
| ⁿ√x | 3.0000 |
|---|---|
| Square root | 9.0000 |
Frequently asked questions
Can I take the cube root of a negative number?
Yes. Odd roots of negative numbers are negative, for example the cube root of −27 is −3.
How is a root related to an exponent?
The nth root is the same as raising to the power 1/n.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.