Square Root Calculator
Calculate square roots, cube roots and any nth root to 14 significant digits, check whether a number is a perfect square or cube, and see the simplified radical form — for example √72 = 6√2. Negative numbers get the real answer for odd roots and the imaginary answer for square roots.
This tool runs entirely in your browser.
How to use the Square Root Calculator
- 1Enter a number.
- 2Choose square root, cube root or nth root (and n).
- 3Read the root, whether it is a perfect power and the simplified radical.
What is the Square Root Calculator?
A radical is simplified by pulling out every factor that is a perfect power: 72 = 36 × 2, and √36 = 6, so √72 = 6√2. The same works for cube roots: ∛54 = 3∛2 because 54 = 27 × 2.
Even roots of negative numbers are not real; the square root of −9 is 3i in complex numbers. Odd roots of negatives are real: ∛−8 = −2. Simplified radicals are shown for whole numbers up to one trillion.
Frequently asked questions
How do I know if a number is a perfect square?
Its square root is a whole number — 144 is (12²), 150 is not. The calculator tells you either way.
Why do some roots look rounded?
Most roots are irrational and never end, so they are shown to 14 significant digits; the simplified radical form is exact.
Is the Square Root Calculator free and private?
Yes. The Square Root Calculator is free, needs no account, and runs entirely in your browser. What you type is never sent to a server or stored.
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