How to Use the Square Root Calculator
Square roots appear in geometry, physics, statistics, and everyday problem-solving. This calculator finds exact and decimal square roots instantly.
Step-by-Step Instructions
- 1 Enter the number you want to find the root of.
- 2 Set the root value (2 for square root, 3 for cube root, etc.).
- 3 Click calculate to see the result.
Understanding the Inputs
Number
The number you want to find the root of. For the square root of 81, enter 81 and the result is 9. For cube root of 125, enter 125 with root value 3 and the result is 5. This can be any non-negative number for even roots, or any real number for odd roots.
How to find it: This is the number under the radical sign. For geometry problems, it may be an area (to find side length of a square) or a volume (to find side length of a cube). For physics, it might come from a formula like the Pythagorean theorem.
Why it matters: The number n is the value whose root you are calculating. The root is the number that must be multiplied by itself root-times to equal n. For square roots, finding the number that squared equals n is essential in geometry, finance, and physics problems.
Type: number · Default: 0
Root Value
The degree of the root to calculate. Default 2 computes the square root. Change to 3 for cube root (the number that cubed equals n), 4 for fourth root, and so on. A root of 2 on 16 gives 4, while root of 4 on 16 gives 2.
How to find it: This small number is written in the crook of the radical symbol. For square roots it is usually omitted (assumed 2). Cube roots are written with a small 3. Higher roots have their index shown explicitly in textbooks and problems.
Why it matters: The root value determines how many times a number must multiply by itself to reach n. A square root (2) is the most common, but cube roots appear in volume calculations and higher roots in scientific formulas.
Type: number · Default: 2
Tips & Best Practices
- ✓ Perfect squares (like 4, 9, 16, 25) have whole number square roots.
- ✓ Most square roots are irrational numbers with infinite decimal places.
- ✓ For negative numbers, the square root is an imaginary number (i x v|x|).
Try the Square Root Calculator
by CalculatorPro Tools · Updated 2026-07-29