Square Root Calculator

The square root of n is the non-negative number that squares to n.

About this calculator

The square root of n is the non-negative number that squares to n. Enter 144 and you get 12 exactly. Enter 50 and you get about 7.071 plus the simplified form 5√2.

Perfect squares — 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144 — have integer roots. For everything else the decimal keeps going; simplified radical form is often what teachers want on paper.

Pair with the [[square]] calculator to check n², the [[simplify-radicals]] tool to factor the radicand, and the [[root]] calculator for nth roots. For side lengths from areas use [[pythagorean]].

Common uses

  • Find √144 or other perfect squares for homework
  • Convert area to side length for a square plot
  • Check whether a number is a perfect square
  • Get simplified radical form like 2√18 → 6√2
  • Estimate square roots between known perfect squares

Frequently asked questions

What is the square root of 144?

√144 = 12 exactly because 12 × 12 = 144. The simplified form is also just 12 with no radical left inside.

Can you take the square root of a negative number?

Not in the real number system. √−4 has no real answer. Complex numbers extend this, but this calculator stays with real results.

What is simplified radical form?

Pull out the largest perfect-square factor. √50 = √(25 × 2) = 5√2. The number under the radical should have no perfect-square factors left.

How is square root related to exponents?

√n equals n raised to the 1/2 power. So √144 = 144^(1/2) = 12. See the [[fractional-exponents]] calculator for more.