Square Root Calculator
The square root of a number is the value that, multiplied by itself, gives the original number. Enter a number to see its square root, with decimals when the answer is not whole.
- Free
- Works offline after your first visit
- Saves on this device
- No sign-up
- Updated
How it works
To find a square root, ask which number times itself gives the one you started with. Nine has a square root of three, because three times three is nine.
Negative numbers do not have a real square root, so this calculator takes zero and positive numbers only.
Worked example
The square root of 144 is 12.
Questions
Why do positive numbers have two square roots?
Both a positive and a negative number square to the same positive result. The calculator gives the positive one, which is called the principal square root.
What is a perfect square?
A perfect square is a whole number whose square root is also whole, such as 25, which has a square root of five.
Can I find the square root of a fraction?
Yes. Enter the decimal form of the fraction. The square root of a fraction is the square root of its top number over the square root of its bottom number.
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