How to use the Square Root Calculator
- Enter the number.
- Choose square root, cube root, or another root.
- Read the result and the simplified radical.
What does this tool do?
The square root of a number is the value that, multiplied by itself, gives that number: √49 = 7. A cube root does the same with three factors: ∛27 = 3.
For whole numbers, the calculator also shows the simplified radical — pulling perfect squares out from under the root sign, the way algebra classes expect.
Why use it?
- Simplifies radicals automatically.
- Handles cube roots of negative numbers (∛−8 = −2).
- Shows a check so you can verify the result.
Example: simplifying √72
72 = 36 × 2, and 36 is a perfect square. So √72 = √36 × √2 = 6√2 ≈ 8.485.
The formula
ⁿ√x = x^(1/n)
√(a × b) = √a × √b
Accuracy and limits
- Even roots of negative numbers (like √−4) aren't real numbers, so the calculator explains this instead of returning an error code.
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Frequently asked questions
Is the square root of 2 a fraction?
No. √2 is irrational: its decimals (1.41421356…) never end or repeat, so it can't be written exactly as a fraction.
Last reviewed by the M2Toolkit team.