Everyday mathematics

Square Root Calculator

Find the non-negative real square root of a number and check it by squaring the result. This is the principal root; an equation y² = x can also have the negative solution.

  • Explicit formulas and worked examples
  • Check your inputs, then calculate
  • Data is calculated in this browser only

Check the stated input format, calculation convention and limits before using the result.

Your inputs

Local calculation

Check the example inputs, then calculate. Your values stay in this browser.

Negative inputs require complex numbers, which this tool does not model.

Calculation notes

Understand the Square Root Calculator

Square Root Calculator validates number before applying the displayed equation. Negative inputs require complex numbers, which this tool does not model.

Formula and logic

What is the formula for the Square Root Calculator?

Square Root Calculator: root = √x; root × root = x. Input definitions: value = Number. Use the selected convention throughout the calculation.

Worked example

How can I reproduce the Square Root Calculator example?

Square Root Calculator baseline input: Number: 81. Output: Result = 9. Substitute these values into the displayed equation to reproduce the result.

How to read the result

How should I interpret the Square Root Calculator result?

  • Read result with its stated unit and convention. The default example and the independent worked scenario use different inputs, so compare the assumptions before comparing the numbers.
  • Change one input at a time and use the equation to explain the result; do not mix unit, grade-scale, time-zone or rounding conventions across comparisons.
Limits and assumptions

What limits apply to the Square Root Calculator?

  • Negative inputs require complex numbers, which this tool does not model.
  • Irrational roots are displayed as floating-point approximations.

Content and calculation reviewed:

Understand the calculation

How to use it and the math behind it

Read the complete explanation

Four steps to check your inputs and results

  1. Find the non-negative real square root of a number and check it by squaring the result. This is the principal root; an equation y² = x can also have the negative solution.
  2. Enter Number in the stated format. Baseline values are for reproduction.
  3. Check the output unit and convention: Read result with its stated unit and convention. The default example and the independent worked scenario use different inputs, so compare the assumptions before comparing the numbers.
  4. Change one input and compare the result. Negative inputs require complex numbers, which this tool does not model. Irrational roots are displayed as floating-point approximations.

Square Root Calculator: calculation relationships

The principal square root is the nonnegative number whose square equals the input. For 2 the result is approximately 1.414213562373; squaring that approximation nearly recovers 2. The equation y²=2 has both positive and negative roots, but √2 denotes only the positive one. Increasing an area by four times increases its corresponding linear scale by two times.

root = √x; root × root = x

The detailed guide adds variable definitions, a reproducible example, a practice question and model limitations.

From question to result

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