Square Root of 144

The square root of 144 is exactly 12, because 12 × 12 = 144. The negative number −12 squares to 144 too.

Whole numbers, decimals or fractions like 9/16. Negative numbers have no real root.
Decimal
12
Both real square roots
±12x² = 144 has two real solutions
Perfect power?
Yes
√14412

Show the work

  1. 144 is a perfect square: 122 = 144.
  2. So √144 = 12.

√144 at a glance

Exact value
12
Decimal (10 places)
12
Rounded
12
Perfect square?
Yes — 12²
Rational?
Rational (whole number)
Both square roots
±12
Prime factorization
2⁴ × 3²
Cube root
5.241483

How to simplify √144

Write 144 as a product of primes and halve every exponent. Because each exponent is even, nothing is left under the radical sign:

144 = 2⁴ × 3²
√144 = 2² × 3 = 12

144 has 8 factor pairs (1 × 144, 2 × 72, 3 × 48, 4 × 36, 6 × 24, 8 × 18, 9 × 16, 12 × 12). The pair with two equal numbers, 12 × 12, is what makes it a perfect square — and why it has an odd number of factors.

Every perfect square is also a sum of consecutive odd numbers starting at 1. Here 144 = 1 + 3 + 5 + 7 + … + 23, the first 12 odd numbers.

Where √144 sits between perfect squares

144 is 12². The perfect squares on either side are 121 (11²) and 169 (13²), so the gaps are 23 below and 25 above — consecutive squares always differ by consecutive odd numbers.

1111² = 1211212² = 1441313² = 169√144 = 12
√144 on a number line, with tenths marked between 11 and 13.

Finding √144 with the Babylonian method

Picture a rectangle with an area of 144 and one side x; the other side must be 144 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √144.

xnext = (x + 144 ÷ x) ÷ 2

To show the method at work on a perfect square, start one above the answer, at 13:

StepGuess x144 ÷ xAverageCorrect decimals
113.000000000011.076923076912.03846153851
212.038461538511.961661341912.00006144024
312.000061440211.999938560212.00000000029
412.000000000211.999999999812.0000000000all 10 shown

The count of correct decimals went 1, 4, 9 and all 10 over 4 steps — roughly doubling each time — until the guess matched √144 = 12.0000000000 to every decimal shown.

√144 in geometry and everyday measurements

  • A square room or garden bed covering 144 square feet measures exactly 12 ft (12 ft) along each wall.
  • 144 is not a sum of two whole-number squares — no pair of squares adds up to it — so √144 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 4 × 8 × 8 box, because 4² + 8² + 8² = 144.
RootSimplest formDecimalPerfect square?
√141√14111.8743No
√142√14211.9164No
√143√14311.9583No
√1441212.0000Yes
√145√14512.0416No
√146√14612.0830No
√1477√312.1244No
  • The cube root of 144 is about 5.241483.
  • Taking the square root twice gives the fourth root: √12 ≈ 3.464102.
  • Four times the radicand doubles the root: √576 = 2 × √144 ≈ 24.

Frequently asked questions

What is the square root of 144?

The square root of 144 is 12, because 12 × 12 = 144. Strictly, 144 has two square roots, 12 and −12; the √ symbol means the positive one.

Is the square root of 144 rational or irrational?

Rational. 144 is a perfect square, so its square root is the whole number 12.

Can √144 be simplified?

Yes, all the way to a whole number: √144 = 12.

What is √144 rounded to two decimal places?

√144 is exactly 12, or 12.00 written to two decimal places.

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