Square Root Calculator
Use this square root calculator to find the square root of any non-negative number instantly.
How to Use the Square Root Calculator
Enter a non-negative number to calculate its principal square root. The tool also indicates whether the input is a perfect square.
Practical Example
√144 = 12 because 12 × 12 = 144. For 2, the result is approximately 1.41421356.
Factors That Affect the Result
This calculator returns real square roots, so negative inputs are not supported. Irrational results are displayed as decimal approximations and may be rounded.
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Cube Root Calculator · Exponent Calculator · Scientific Notation Calculator · Rounding Calculator · Prime Number Checker
Frequently Asked Questions
What is the square root of zero?
It is zero.
Can a negative number have a real square root?
No. Negative numbers require the complex number system for square roots.
What is a perfect square?
It is a number whose principal square root is an integer.
Understanding Square Roots
The square root of a number is a value that, when multiplied by itself, produces the original number. For example, the principal square root of 81 is 9 because 9 × 9 = 81. Perfect squares produce integer roots, while many other positive numbers produce irrational decimal results.
Exact and Approximate Results
A calculator may display a rounded decimal for values such as √2 even though the exact value continues indefinitely. Keep additional digits when the result will be used in another calculation, then round at the final step. In ordinary real-number calculations, negative inputs do not have real square roots; complex-number mathematics represents them using the imaginary unit.
Square roots appear in geometry, statistics, engineering, distance formulas, and algebra. When solving an equation such as x² = 81, remember that both +9 and -9 satisfy the equation even though the principal square-root function itself returns the nonnegative root.