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Percentage Calculator
Find a percentage of a number, what percent one number is of another, or the whole from a part.
Square Root Calculator
Find the square root of any number, with the simplified radical form for whole numbers.
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How to use this calculator
Enter your values. The result updates as you type; press Calculate to confirm and jump to the result on mobile. Use Share to send the calculator with your result.
What is a square root?
The square root of x is the number that multiplied by itself gives x: √49 = 7 because 7 × 7 = 49. Every positive number has two square roots (7 and −7); the calculator shows the positive (principal) one.
Simplifying radicals
Pull the largest perfect square out of the number: √72 = √(36 × 2) = 6√2.
Perfect squares
| n | n² |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 16 |
| 5 | 25 |
| 6 | 36 |
| 7 | 49 |
| 8 | 64 |
| 9 | 81 |
| 10 | 100 |
| 11 | 121 |
| 12 | 144 |
| 13 | 169 |
| 14 | 196 |
| 15 | 225 |
Frequently asked questions
What is the square root of 20?
About 4.4721, or 2√5.
What is the square root of 2?
About 1.41421356.
About this tool
- Written by
- [Author: to be assigned]
- Reviewed by
- Formula tests passed · human review pending
- Last updated
- 31 Oct 2026
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