Skip to main content
MathKit

Square Root of 27

The square root of 27 is about 5.1962. Square roots reverse squaring and are essential in geometry and the quadratic formula.

No number times itself can equal 27: perfect squares only ever leave 0 or 1 when divided by 4, and 27 leaves 3 — so √27 is irrational, its decimal never ending nor repeating. The ladder fences it between √5 = 25 and √6 = 36, the nearer fence just 2 away against 9 on the far side. Rounded to two places, the estimate is 5.20 — within one hundredth of the true value. Irrational roots are no curiosity: the diagonal of a unit square is √2, the first irrational anyone ever meets, and every slanted right triangle produces its own.

Square-root reference row for 27 — √27 to six decimal places
ExpressionValue
√275.196152

Frequently asked questions

What is the square root of 27?

The square root of 27 is about 5.1962. It is the number that, multiplied by itself, gives 27.

Is 27 a perfect square?

No — 27 sits between the perfect squares 25 and 36, so its square root is irrational.

What does √ mean?

√ is the radical sign, short for square root. √27 asks: which number times itself equals 27? Here the answer is about 5.1962.

Related calculators

Related tables