Square Root of 24

The square root of 24 is 2√6 in simplest radical form, or about 4.8989794856 as a decimal.

Whole numbers, decimals or fractions like 9/16. Negative numbers have no real root.
Simplest radical form
2√6
Decimal
4.8989794856
Both real square roots
±4.8989794856x² = 24 has two real solutions
Between
4² = 16 and 5² = 25so the root is between 4 and 5
Perfect power?
No
√244.8989794856= 2√6

Show the work

  1. Prime-factor the radicand: 24 = 23 × 3 = (22) × 2 × 3.
  2. Each pair of identical factors comes out of the radical as a single factor: √24 = 2√6.
  3. Decimal value: √24 ≈ 4.8989794856.
  4. Check: 4.89897948562 ≈ 24.

√24 at a glance

Exact value
2√6
Decimal (10 places)
4.8989794856
Rounded
4.9 · 4.90 · 4.899
Perfect square?
No — between 4² and 5²
Rational?
Irrational
Both square roots
±4.898979
Prime factorization
2³ × 3
Cube root
2.884499

How to simplify √24

Look for the largest perfect square that divides 24. Here it is 4 (2²), because 24 = 4 × 6 and 6 has no square factor left:

√24 = √(4 × 6) = √4 × √6 = 2√6

The prime factorization tells the same story: 24 = 2³ × 3. Each pair of equal primes leaves the radical as one factor, so 2 comes out and 2 × 3 stays inside.

Check: (2√6)² = 2² × 6 = 4 × 6 = 24. As a decimal, 2√6 = 2 × 2.4494897428 ≈ 4.8989794856.

Where √24 sits between perfect squares

16 = 4² and 25 = 5² are the nearest perfect squares, so √24 lies between 4 and 5. 24 is 8 above 16 and 1 below 25, so the root is closer to 5.

√24 ≈ 4 + (24 − 16) ÷ (25 − 16) = 4 + 8/9 ≈ 4.8889
  • Straight line between 16 and 25: 4.8889 (0.21% low)
  • Tangent from 4, i.e. 4 + 8 ÷ 8: 5.0000 (2.06% high)
  • Tangent from 5, i.e. 5 − 1 ÷ 10: 4.9000 (0.02% high)

For √24 the tangent at 5 wins, missing by only 0.001. Tangent estimates shine when the number sits close to a perfect square — here 24 is just 1 below 25.

44² = 1655² = 25√24 ≈ 4.899
√24 on a number line, with tenths marked between 4 and 5.

Finding √24 with the Babylonian method

Picture a rectangle with an area of 24 and one side x; the other side must be 24 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √24.

xnext = (x + 24 ÷ x) ÷ 2

Start from the nearest whole number, 5 (5² = 25):

StepGuess x24 ÷ xAverageCorrect decimals
15.00000000004.80000000004.90000000002
24.90000000004.89795918374.89897959186
34.89897959184.89897937934.8989794856all 10 shown

The count of correct decimals went 2, 6 and all 10 over 3 steps — roughly doubling each time — until the guess matched √24 = 4.8989794856 to every decimal shown.

√24 as a continued fraction

Every irrational square root has a continued fraction that repeats. For √24 the pattern is [4; 1, 8] with the block of 2 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √24 is irrational.

Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:

FractionDecimalError
4/14.00000000009.0 × 10⁻¹
5/15.00000000001.0 × 10⁻¹
44/94.88888888891.0 × 10⁻²
49/104.90000000001.0 × 10⁻³
436/894.89887640451.0 × 10⁻⁴
485/994.89898989901.0 × 10⁻⁵

The same fractions solve Pell’s equation, x² − 24y² = 1. Its smallest solution in positive whole numbers is x = 5, y = 1.

√24 in geometry and everyday measurements

  • A square tile with an area of 24 square inches has sides about 4.899 in long.
  • 24 is not a sum of two whole-number squares — the prime factor 3 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √24 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 2 × 2 × 4 box, because 2² + 2² + 4² = 24.
  • Since √24 = 2√6, a length of √24 is exactly 2 copies of the length √6 laid end to end.
RootSimplest formDecimalPerfect square?
√21√214.5826No
√22√224.6904No
√23√234.7958No
√242√64.8990No
√2555.0000Yes
√26√265.0990No
√273√35.1962No
  • The cube root of 24 is about 2.884499.
  • Four times the radicand doubles the root: √96 = 2 × √24 ≈ 9.797959.

Frequently asked questions

What is the square root of 24?

The square root of 24 is 2√6 in simplest radical form, which is about 4.8989794856. The negative root, −4.898979, also squares to 24.

Is the square root of 24 rational or irrational?

Irrational. 24 is not a perfect square — it falls between 16 and 25 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.

Can √24 be simplified?

Yes. The largest perfect square dividing 24 is 4, so √24 = √4 × √6 = 2√6.

What is √24 rounded to two decimal places?

√24 ≈ 4.90 to two decimal places (4.9 to one, 4.899 to three). Check: 4.90² = 24.01, close to 24.

Need a different value? Use the Square root calculator, or browse the Square roots 1–1,000.