Square Root Calculator

Use the free Square Root Calculator to instantly find the square root of any non-negative number. Shows the decimal result, checks for perfect squares, and simplifies radical expressions.

866.3K usesUpdated · 2026-04-28Runs locally · zero upload

How to Use the Square Root Calculator

The Square Root Calculator delivers instant, accurate square root results for any non-negative number.

  1. Enter a Number — Type any non-negative integer or decimal into the input field.
  2. Read the result — The Square Root Calculator immediately shows the decimal approximation to six places, a perfect-square badge, and — for integer inputs — the simplified radical form.

There is no button to press. The Square Root Calculator updates as you type, making it ideal for fast homework checks or engineering calculations.

Formula & Theory — Square Root Calculator

The Square Root Calculator is based on the definition of the square root:

If x² = n, then x = √n   (for n ≥ 0)
Symbol Meaning
n The input number (non-negative)
√n The principal (positive) square root of n
x The result: x × x = n

Radical simplification: For an integer input n, the Square Root Calculator finds the largest perfect-square factor k² of n, then rewrites the result as:

√n = √(k² × r) = k√r

For example: √72 = √(36 × 2) = 6√2.

Perfect Squares

A number is a perfect square if its square root is an integer. The Square Root Calculator checks this automatically. Common examples: √4 = 2, √9 = 3, √25 = 5, √100 = 10.

Use Cases for the Square Root Calculator

The Square Root Calculator is an essential tool for students, teachers, and professionals:

  • Mathematics homework — Find square roots quickly and verify whether answers are exact or irrational using the Square Root Calculator.
  • Geometry — Calculate the side length of a square from its area, or find the hypotenuse via the Pythagorean theorem.
  • Physics and engineering — Compute root-mean-square (RMS) values, signal amplitudes, and other quantities that involve square roots.
  • Finance — Volatility and standard deviation formulas in finance rely on square roots; the Square Root Calculator speeds up manual checks.
  • Standardized tests — Quickly simplify radical expressions on algebra and geometry sections of exams.

With exact decimal output, perfect-square detection, and simplified radical forms, the Square Root Calculator is the most complete square-root tool available online.

Frequently asked questions about Square Root Calculator

What is a square root?

The square root of a number n is a value x such that x² = n. The Square Root Calculator finds this value and displays it as a decimal, and also simplifies the radical form when the input is an integer.

What is a perfect square?

A perfect square is an integer whose square root is also an integer (e.g., 4, 9, 16, 25). The Square Root Calculator automatically detects and labels perfect squares.

How does the Square Root Calculator simplify radicals?

For integer inputs, the Square Root Calculator extracts the largest perfect-square factor. For example, √72 = √(36 × 2) = 6√2.

Can the Square Root Calculator handle decimals?

Yes. The Square Root Calculator accepts any non-negative decimal and returns the result to six decimal places.

Is my data stored?

No. All calculations happen in your browser; nothing is sent to a server.