Square Root Calculator

Find the square root of any number — the value that, when multiplied by itself, gives your number.

How it is calculated

The square root is the number that produces your input when multiplied by itself.

If the result is a whole number, the input is a perfect square.

Negative numbers have no real square root, because any real number multiplied by itself is positive.

Formula

Square root: √n = x where x × x = n

Also written: n^(1/2)

Worked example

Finding the square root of 144.

Number: 144

Look for a number that multiplied by itself gives 144

12 × 12 = 144

144 is so a perfect square

Answer: √144 = 12

Frequently asked questions

Why can't I take the square root of a negative number?

Because a positive number times a positive number is positive, and a negative number times a negative number is also positive. No real number, when squared, gives a negative answer. Mathematicians use imaginary numbers to handle this, but there is no real answer.

Doesn't every number have two square roots?

Yes — both 12 and −12, when squared, give 144. By agreement, the √ symbol means the positive root, which is what this calculator shows.

What is a perfect square?

A number whose square root is a whole number — like 1, 4, 9, 16, 25, 36, and so on.