Skip to main content

Square Root Calculator

Use this square root calculator to enter any number and quickly find its square root, decimal value, and perfect square result online.

Square Root Calculator

Enter any number. Decimals and negative numbers are supported.

Try:

Enter values above to see results

About This Square Root Calculator

This square root calculator helps you find the square root of a number without solving it manually. Enter a value, click calculate, and the tool will return the result in a clear format.

It is useful for algebra homework, geometry problems, area calculations, Pythagorean theorem questions, and everyday math checks. You can use it with perfect squares, decimals, and non-perfect square values.

What Is a Square Root?

A square root is a number that gives the original value when multiplied by itself. For example, 5 is the square root of 25 because 5 × 5 = 25.

The square root symbol is √. When you see √n, it means you are looking for the number that can be multiplied by itself to produce n.

How to Use the Square Root Calculator

Follow these steps:

  1. Enter the number in the input field.
  2. Click the calculate button.
  3. Review the square root result.
  4. Check whether the number is a perfect square.
  5. View the decimal or exact form if the calculator provides it.

This process is helpful when you need a quick result and do not want to estimate the answer by hand.

Square Root Formula

The basic formula is:

If x² = n, then x = √n

Here, n is the original number and x is its square root. If x multiplied by itself equals n, then x is a square root of n.

How to Find Square Root Manually

If you are learning how to find square root values manually, start by checking whether the number is a perfect square. Perfect squares have whole-number roots, such as 4, 9, 16, 25, 36, 49, and 100.

For non-perfect squares, the result is usually a decimal. You can estimate the value by finding the two perfect squares around it. For example, 10 is between 9 and 16, so √10 is between 3 and 4.

This is also the simplest way to understand how to find the square root of a number before using an online tool.

Square Root Examples

Here are a few common examples:

NumberSquare Root
42
93
164
255
10010

The square root of 100 is 10 because 10 × 10 = 100. The square root of 10 is about 3.162 because 10 is not a perfect square.

Perfect Squares

A perfect square is a number with a whole-number square root. Examples include 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100.

If a number is not a perfect square, the answer may appear as a decimal or radical form. For example, the square root of 8 is about 2.828, but it can also be written in simplified radical form.

Simplifying Square Roots

Sometimes you may need to simplify square root values instead of converting them fully into decimals. This is common in algebra when the answer should stay in radical form.

For example, √8 can be simplified as 2√2. If you need to simplify square root expressions, look for the largest perfect square factor inside the number. This calculator shows that simplified radical form automatically for whole numbers.

Principal Square Root

Positive numbers technically have two roots: one positive and one negative. For example, both 3 and -3 produce 9 when multiplied by themselves.

However, the square root symbol usually refers to the principal square root, which is the non-negative result. That is why √9 is normally written as 3.

Can You Find the Square Root of a Negative Number?

Negative numbers do not have real square roots. When you enter a negative number, this calculator shows the result using the imaginary unit i.

√-9 = 3i

For most basic math, square root answers focus on real numbers, but imaginary results are shown here when the number is negative.

When Should You Use This Tool?

A square root calculator is useful when you need fast help with:

  • Algebra homework
  • Geometry problems
  • Area and side-length calculations
  • Pythagorean theorem questions
  • Perfect square checks
  • Scientific calculations
  • Decimal square root values
  • Radical expression checks

Related Calculators

You may also find these tools useful:

  • Pythagorean Theorem Calculator
  • Square Calculatorcoming soon
  • Cube Root Calculatorcoming soon
  • Root Calculatorcoming soon
  • Exponent Calculatorcoming soon
  • Scientific Calculatorcoming soon
  • Algebra Calculatorcoming soon

Start Calculating

Enter your number above and use the square root calculator to get the result quickly. Review whether your answer is a perfect square, decimal, or simplified form.

Frequently Asked Questions

What is the square root of a number?

It is a value that produces the original number when multiplied by itself. For example, 5 is the square root of 25 because 5 × 5 = 25.

Can I calculate decimals?

Yes. Decimal inputs can be used, and the result is shown as a decimal. For example, √6.25 = 2.5.

Can a square root be negative?

The principal root shown by the √ symbol is not negative, but a positive number has both a positive and a negative root in equation solving, which is why the tool also reports the ± value.

Is a square root the same as exponent 1/2?

Yes. Taking the square root of a number is the same as raising it to the power of 1/2.

What is a perfect square?

A perfect square is a number with a whole-number square root, such as 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100. The calculator tells you whether your number is one.

Can it simplify a square root?

Yes. For whole numbers that are not perfect squares, it factors out the largest perfect square and shows the simplified radical form, such as √8 = 2√2.

What happens with a negative number?

Negative numbers have no real square root, so the calculator shows the result using the imaginary unit i. For example, √-9 = 3i.