Square Root Calculator

Square root of a non-negative number.

Inputs

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Formula

√n = the non-negative x such that x² = n

Every non-negative number has a unique non-negative square root. The calculator also shows a 'squared check' — multiplying the result by itself — so you can confirm the answer.

Worked example

√144 = 12 because 12 × 12 = 144. The squared-check line confirms 12² returns 144.000000.

Where this can give the wrong answer

  • Negative inputs are rejected — square roots of negative numbers aren't real numbers (they'd be imaginary, like √−1 = i).
  • Perfect squares (1, 4, 9, 16, …) give exact integer results; non-perfect squares (e.g. √2 ≈ 1.414214) are shown as decimals.
  • √0 = 0 — zero is the only number whose square root is itself.

FAQ

Floating-point arithmetic can't represent every decimal exactly. The check uses six decimal places — tiny drift (e.g. 11.999999²) is normal and doesn't mean the root is wrong.