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Quick answer: enter any number above — get its square root instantly, or switch tabs for cube roots and any nth root, each with a verification showing the answer raised back to the original power.
Square root calculator
Short answer: the square root of a number is the value that, multiplied by itself, gives the number — √144 = 12. Enter any non-negative number above for an instant high-precision result.
Cube root calculator
Short answer: the cube root is the value that, cubed, gives the number — ∛27 = 3. Unlike square roots, cube roots work for negative numbers too (∛−8 = −2). Use the Cube root tab above.
Nth root calculator
Short answer: need the 4th or 5th root? The nth root tab takes any root degree — e.g. the 4th root of 16 is 2, because 2⁴ = 16. Every answer shows its verification.
Frequently asked questions
What is a square root?
The square root of a number x is the value that gives x when multiplied by itself. √25 = 5 because 5 × 5 = 25. Every positive number has two square roots (positive and negative); calculators show the principal (positive) root.
How do you find the square root of a number?
For perfect squares (16, 81, 144), factor them: √144 = √(12 × 12) = 12. For anything else, enter it above — the calculator gives a high-precision answer instantly, with a verification step.
What is the cube root of a negative number?
Negative numbers have real cube roots: ∛−8 = −2 because (−2)³ = −8. (Even roots of negatives, like √−4, are not real numbers.) Use the Cube root tab above.
What is an nth root?
The nth root of x is the number that, raised to the power n, equals x. The square root is n=2, the cube root is n=3. The Nth root tab accepts any whole-number degree.
Why do I see so many decimal places?
Most roots are irrational — their decimals never end. The calculator shows 12 significant digits so you can round to whatever precision your homework or work needs.
Is this square root calculator free?
Yes — unlimited calculations, free forever. No account, no limits. Everything runs in your browser.