How to use the square root calculator
Set Number (x) to the value you want to check. Root index (n) starts at 2 for a square root, and a different positive whole number selects another root. Number unit can add a label to the displayed result.
- Enter a value in Number (x), such as
144. - Leave Root index (n) at
2for a square root, or enter another positive whole number. - Enter an optional label in Number unit, such as
m^2. - Select Calculate to display the result, formula, and calculation steps.
- Select Copy result or Download result (.txt) to keep the plain-text output.
Calculate a square root or nth root
The Square Root Calculator evaluates x^(1/n), the value r where r^n = x. With Root index (n) set to 2, the calculation looks like this:
Number (x): 144
Root index (n): 2
Result: 12After you select Calculate, the result panel shows Result, Number, and Root index. Formula & steps lists the entered values, formula, computed value, and verification. Zero returns zero for every positive root index. A positive Number (x) produces a real non-negative root.
What negative numbers do in the nth root calculator
A negative Number (x) produces a real result when Root index (n) is odd. For example:
Number (x): -8
Root index (n): 3
Result: -2An even Root index (n) with a negative Number (x) shows an error. The calculator reports real roots, so it does not return a complex result for that input.
Number and root index input rules
Number (x) accepts digits with an optional minus sign and a decimal point, including 0.5 and .5. Blank input, scientific notation, a leading plus sign, and other text show an error. The absolute value cannot exceed 1e15.
Root index (n) must contain a positive whole number from 1 through 1000. A blank, decimal, negative, or larger index shows an error instead of a result.
What Number unit changes
Number unit adds the trimmed text you enter to the displayed result. The calculator does not convert, check, or reduce units, so the entry stays as a label:
Number (x): 9
Root index (n): 2
Number unit: cm^2
Result: 3 cm^2Select Reset to clear Number (x) and Number unit, restore Root index (n) to 2, and hide the current result. The calculation values stay in the browser; this page's calculator script makes no request containing them.
Copy or download the result
Copy result and Download result (.txt) use the plain-text result created after a calculation. The text includes the input values, the result, and the numbered steps.
If copying does not work, the page shows the result text so you can select it and copy it manually. Changing an input hides the current result until you select Calculate again.
Square Root Calculator or another math calculator?
Start with Math Calculators when you are choosing a calculator for a different kind of problem. The Exponent Calculator is the better choice when you need a base raised to a real exponent. The Algebra Calculator fits one-variable equations, quadratic equations, or small systems of linear equations.
Frequently asked questions
How do I calculate a square root?
Enter the number in Number (x), leave Root index (n) at 2, and select Calculate. The result includes the formula and calculation steps.
How do I use an nth root calculator?
Enter the number and a positive whole number in Root index (n), then select Calculate. Root index 3 gives a cube root, while 4 gives a fourth root.
Can a square root calculator handle a negative number?
A negative number works when Root index (n) is odd, such as -8 with index 3. A negative number with an even index shows an error because the result is not real.
Can I add units to a root result?
You can type a label in Number unit and the calculator will append it to the result. It treats that entry as text and does not convert or validate the unit.