What is a perfect square?

A perfect square is a number whose square root is a whole number, like 4, 9, 16, 25.

Can I calculate square root of negative numbers?

No, the square root of negative numbers is undefined in real numbers.

Yes, this tool is completely free and works directly in your browser.

Calculate the square root of any positive number.

Enter a Number

√? =

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√x is the number that, when multiplied by itself, equals x. √16 = 4 because 4 × 4 = 16.

If √x is a whole number, x is a perfect square. The tool identifies perfect squares automatically.

Most square roots are irrational (non-terminating decimals). Results shown to 8 decimal places.

Square roots of negative numbers are undefined in real numbers. The tool handles this case.

Uses the built-in Math.sqrt() function for accurate floating-point calculation.

Calculate hypotenuse or side length: c = √(a² + b²). Essential for geometry.

Find distance between points: d = √((x₂-x₁)² + (y₂-y₁)²). Used in mapping and physics.

Statistics calculations involve √(variance). Square roots are fundamental to statistics.

Given square area, find side length. A 144 sq.ft room is 12 ft × 12 ft (√144 = 12).

Identify perfect square factors to simplify. √72 = √(36 × 2) = 6√2.

Many engineering formulas involve square roots: stress, vibration, signal analysis.