Square Root Calculator

Enter a real number to calculate its principal square root. Integer inputs up to 1 trillion also get an exact simplified radical, perfect-square status, both real roots when applicable, and a square-back check.

Number

Decimal places

For positive real x, √x means the principal non-negative square root. The second real solution of y²=x is −√x. Negative inputs are reported in complex-number notation.

—Principal square root

—Exact radical

—Other root

—Perfect square?

—Square-back check

√x

Formula and interpretation

√x is the non-negative number whose square equals x.

Negative inputs have no real square root; complex-number workflows are separate.