EachCalculatorSquare Root Calculator
Calculate the square root of any non-negative number, or any nth root (cube root, fourth root, and beyond).
Square Root
9
Perfect square
2th Root
9
How It Works
Square roots
The square root of a number is the value that, multiplied by itself, gives the original number. Negative numbers don't have a real square root.
nth roots
An nth root generalizes this to any power — a cube root (n=3) is the value that, cubed, gives the original number. Odd roots (like cube roots) can be taken of negative numbers; even roots cannot.
Example Calculation
The square root of 81 is 9 (a perfect square). The cube root of 27 is 3.
Common Mistakes
- Trying to take an even root (square root, 4th root, etc.) of a negative number — this has no real-number answer.
- Assuming every square root is a whole number — most numbers have irrational (non-terminating) square roots.
Frequently Asked Questions
- What is a perfect square?
- A perfect square is a number whose square root is a whole number, like 4, 9, 16, or 81 — this calculator flags when your result is one.
- Can you take the square root of a negative number?
- Not as a real number — that requires imaginary numbers, which this calculator doesn't compute. Odd roots (cube root, 5th root, etc.) of negative numbers work fine and give a negative result.