Square Root Calculator
Find the square root of any number with exact and decimal results shown step by step, free and instant in your browser.
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How to use this calculator
- Enter a number.
- Press Calculate.
How it works
Finds the number that, multiplied by itself, gives your input.
Worked example
√144. = 12.
Common mistakes
- Expecting an exact value for non-perfect squares — most are irrational.
- Forgetting that negative numbers have no real square root.
Frequently asked questions
Does a negative number have a square root?
Not a real one — the square root of a negative is an imaginary number.
Why isn't √2 a neat number?
It's irrational — its decimals go on forever without repeating, so it's shown rounded.
Can I take the square root of a negative number?
Not as a real number — negative inputs have no real square root (the answer would be imaginary).
Why does every number have two square roots?
Because both +12 and −12 squared give 144. This tool shows the positive (principal) root.
Related tools
- Nth Root Calculator
- Exponent (Power) Calculator
- Modulo Calculator
- Prime Number Checker
- Cube Root Calculator
- Engineering Prefix Calculator
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Cite this tool
Zerdly. (2026). Square Root Calculator. Retrieved from https://www.zerdly.com/tools/square-root-calculator/
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.