Square Root Calculator
Square root calculator: get the square root, cube root and square of any number, and check whether it is a perfect square, free and fast.
Editorial review: Farrow (pseudonym; identity and professional credentials are not disclosed). This page is for educational purposes, not professional advice.
Your inputs
Results update as you type. Nothing you enter leaves your device.
Results
- Perfect square
- Yes
- Cube root
- 5.241483
- Square
- 20,736
Example with the starting values
These results use the calculator's initial inputs. Change the values above to calculate your own estimate.
Inputs
- Number
- 144
Results
- Square root
- 12
- Perfect square
- Yes
- Cube root
- 5.241483
- Square
- 20,736
How does the Square Root Calculator work?
The square root of x is the number that multiplied by itself gives x. √144 = 12 because 12 × 12 = 144. Numbers like 2 or 50 have irrational roots, shown here to six decimal places.
A perfect square is a whole number whose square root is also a whole number, like 1, 4, 9, 16 and 25. Negative numbers have no real square root, so the calculator shows the root of the absolute value as an imaginary result.
Frequently asked questions
What is the square root of 2?
√2 is about 1.414214. It is irrational, so its decimal never ends or repeats.
Can you take the square root of a negative number?
Not within real numbers. √−9 = 3i, where i is the imaginary unit.
How do I estimate a square root by hand?
Find the two perfect squares around it. √50 sits between √49 = 7 and √64 = 8, so it is a little over 7. The exact value is 7.0711.
What is the square root of 16?
√16 = 4, since 4 × 4 = 16. Every positive number also has a negative root, but the principal root is the positive one.