Square Root of 27

Calculate √27 instantly — exact value, step-by-step explanation, and properties.

√27 =
5.1961524227
Simplified: 3√3
≈ Irrational Number

How to Calculate √27

The square root of 27 is approximately 5.1961524227. Since 27 is not a perfect square, its square root is an irrational number. We know that √25 = 5 and √36 = 6, so √27 falls between 5 and 6. The simplified radical form is 3√3. To estimate manually: start with 5.1, then refine using the Babylonian method — guess a value, divide 27 by it, average the result with your guess, and repeat.

The Babylonian Method (Step by Step)

  1. Start with an initial guess. Since √25 = 5 and √36 = 6, a good starting guess is 5.5.
  2. Divide 27 by your guess: 27 ÷ 5.5 = 4.9091
  3. Average the result with your guess: (5.5 + 4.9091) ÷ 2 = 5.204545
  4. Repeat with the new estimate until you reach the desired precision.
√27 ≈ 5.1961524227

Properties of √27

Perfect Square?

No

27 is not a perfect square. Its root is irrational.

Decimal Value

5.1961524227

Rounded to 10 decimal places.

Simplified Form

3√3

Simplified by extracting perfect square factors from the radicand.

Square Root Symbol

√27

Also written as 27^(1/2) or 27^0.5 in programming.

Related Square Root Values

Reference table of square roots near 27 for quick comparison.

Number Square Root Perfect Square? Simplified
√25 5 Yes 5
√24 4.898979 No 2√6
√30 5.477225 No
√32 5.656854 No 4√2
√20 4.472135 No 2√5
√36 6 Yes 6
√18 4.242640 No 3√2
√16 4 Yes 4
√15 3.872983 No
√40 6.324555 No 2√10

Frequently Asked Questions

What is the square root of 27?

The square root of 27 is approximately 5.1961524227. This is an irrational number, which can be written in simplified radical form as 3√3.

Is 27 a perfect square?

No, 27 is not a perfect square. Its square root (5.1961524227...) is an irrational number that cannot be expressed as a simple fraction.

How do you calculate √27 by hand?

To calculate √27 by hand, use the Babylonian method: (1) Make an initial guess — since √25 = 5 and √36 = 6, start with 5.5. (2) Divide 27 by your guess. (3) Average the result with your guess. (4) Repeat steps 2-3 until you reach desired precision.

What is √27 in simplified radical form?

√27 can be simplified to 3√3. This is found by factoring out the largest perfect square from 27.

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