Square root calculator
Calculator
The calculator needs JavaScript. The tables below give the same numbers for common cases.
How it is worked out
- The square root of x is the number that gives x when multiplied by itself.
- 8.48528137 × 8.48528137 = 72.
| Inputs | Answer |
|---|---|
| Number: 72 | √72 = 8.48528137. |
| Number: 144 | √144 = 12. |
| Number: 2 | √2 = 1.41421356. |
| Number: 50 | √50 = 7.07106781. |
How to use it
The square root of x is the number that gives x when multiplied by itself. √144 = 12 because 12 × 12 = 144. A whole number that has a whole square root is a perfect square.
For other whole numbers the calculator also gives the simplified radical form: √72 = 6√2, because 72 = 36 × 2 and √36 = 6. Negative numbers have no real square root.
Frequently asked questions
What is the square root of 72?
About 8.4853, or 6√2 in simplified radical form.
What is a perfect square?
A whole number whose square root is also a whole number: 1, 4, 9, 16, 25 …
Can you take the square root of a negative number?
Not within the real numbers; the result is an imaginary number, such as √−4 = 2i.
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
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General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.