Square Root Calculator

A square root calculator finds the number that, when multiplied by itself, produces a given value. For example, the square root of 25 is 5 because 5 x 5 = 25. This tool handles perfect squares, decimals, and large numbers, providing both exact and approximate results.

The calculator also identifies whether a number is a perfect square and can show the step-by-step prime factorization method for finding square roots by hand. This makes it valuable for both quick answers and deeper understanding of how square roots work mathematically.

• Math homework - Find square roots quickly for algebra, geometry, and pre-calculus assignments
• Geometry problems - Calculate distances, diagonals, and side lengths that involve square roots
• Construction - Determine diagonal measurements using the Pythagorean theorem
• Statistics - Compute standard deviation, which requires taking the square root of variance
• Simplifying radicals - Reduce expressions like the square root of 72 to 6 times the square root of 2
• Programming - Verify square root outputs when debugging mathematical code

• Non-perfect squares - Most numbers don't have clean integer square roots, producing irrational decimals
• Simplifying radicals - Breaking down expressions like the square root of 200 into 10 times the square root of 2 requires prime factorization
• Negative numbers - The square root of a negative number involves imaginary numbers (i), which many students find confusing
• Estimation difficulty - Without a calculator, estimating the square root of 50 (somewhere between 7 and 8) requires practice

For perfect squares, the calculator returns the exact integer result. The square root of 144 is exactly 12. For non-perfect squares, it provides a decimal approximation. The square root of 7 is approximately 2.6458. The tool recognizes perfect squares automatically and labels them accordingly.

The prime factorization method breaks the number into its prime factors, then pairs them up. Each pair of identical primes comes out of the radical as a single factor. For example, 72 = 2 x 2 x 2 x 3 x 3. Pair the 2's (one pair) and the 3's (one pair), giving 2 x 3 = 6 outside the radical, with one 2 remaining inside. So the square root of 72 = 6 times the square root of 2.

Example

Find the square root of 180.

Prime factorization: 180 = 2 x 2 x 3 x 3 x 5. Pairs: (2, 2) and (3, 3). Result: 2 x 3 = 6 comes outside. Leftover: 5 stays inside. Square root of 180 = 6 times the square root of 5, which is approximately 13.4164.

• Square root of 64 - Exactly 8 (perfect square: 8 x 8 = 64)
• Square root of 2 - Approximately 1.4142 (one of the most famous irrational numbers)
• Square root of 50 - 5 times the square root of 2, approximately 7.0711
• Square root of 225 - Exactly 15 (perfect square: 15 x 15 = 225)
• Square root of 3 - Approximately 1.7321 (commonly seen in geometry with equilateral triangles)

• Instant answers - Get exact or decimal results immediately without manual computation
• Perfect square detection - Know instantly whether a number has a clean integer square root
• Simplified radicals - See the simplified form automatically, which is essential for math assignments
• Learning tool - The step-by-step prime factorization breakdown teaches the underlying method
• Handles any number - Works with small numbers, large numbers, and decimals without limitations

What is a perfect square?

A perfect square is a number whose square root is a whole number. Examples include 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, and so on. These are the result of multiplying an integer by itself. Numbers between these values are not perfect squares and have irrational square roots.

Can you take the square root of a negative number?

Not in the real number system. The square root of a negative number produces an imaginary number. For example, the square root of -9 is 3i, where i represents the square root of -1. Imaginary numbers are used extensively in engineering, physics, and advanced mathematics.

How do I simplify a square root?

Use prime factorization. Break the number into prime factors, find pairs of identical primes, and move each pair outside the radical as a single factor. Whatever doesn't pair up stays inside. For example, the square root of 48 = the square root of (2 x 2 x 2 x 2 x 3) = 4 times the square root of 3.

What is the square root of 0?

The square root of 0 is 0. Zero is the only number that is its own square root (besides 1). This is because 0 x 0 = 0. It's technically a perfect square.

Why are some square roots irrational?

A square root is irrational when the number isn't a perfect square. Irrational numbers have decimal expansions that never terminate and never repeat. The square root of 2, for instance, is 1.41421356... continuing infinitely with no repeating pattern. This was one of the earliest mathematical discoveries by ancient Greek mathematicians.

How do I estimate a square root without a calculator?

Find the two perfect squares the number falls between. For example, the square root of 30 falls between the square root of 25 (which is 5) and the square root of 36 (which is 6). Since 30 is closer to 25, estimate around 5.4 to 5.5. The actual value is approximately 5.477.