Formula and method
FormulaThe principal square root √x is the non-negative number y for which y² = x.
Real square roots are available for zero and positive values. Negative inputs require complex numbers and are not accepted here.
Worked example
√144 = 12 because 12² = 144.
How to use this calculator
- Enter the values using the labels and units shown.
- Review the live result and supporting details.
- Check the formula, example and assumptions before using the answer.
Assumptions and limits
- Only the principal real root is returned.
Reference
Formula reviewed 2026-07-15