Back to tools
Module · Math · Scientific
Root Calculator
Compute square roots, cube roots and nth roots of any real number. Handles negative radicands and even-order roots correctly.
Result
2√64 =
8
Principal (positive) root: 8 · negative root: −8
Advertisement
Guide
How Root Calculator works
Step 01
Enter the number
The radicand (the value under the root sign).
Step 02
Enter the index
2 for √, 3 for ∛, n for nth root.
Step 03
See result
Real value if defined; note when even root of a negative number has no real solution.
FAQ
Frequently asked
Why does it say 'undefined' for √(−9)?+
The even root of a negative number is not a real number (it would be a complex number).
What's the principal root?+
For even roots, the positive value. For square root of 4, the principal root is 2 (though −2 also works).