Square Root of 185

The square root of 185 is about 13.6014705087. It is irrational and already in simplest form, written √185.

Whole numbers, decimals or fractions like 9/16. Negative numbers have no real root.
Simplest radical form
√185
Decimal
13.6014705087
Both real square roots
±13.6014705087x² = 185 has two real solutions
Between
13² = 169 and 14² = 196so the root is between 13 and 14
Perfect power?
No
√18513.6014705087= √185

Show the work

  1. Prime-factor the radicand: 185 = 5 × 37.
  2. No prime appears 2 or more times, so √185 is already in simplest form.
  3. Decimal value: √185 ≈ 13.6014705087.
  4. Check: 13.60147050872 ≈ 185.

√185 at a glance

Exact value
√185
Decimal (10 places)
13.6014705087
Rounded
13.6 · 13.60 · 13.601
Perfect square?
No — between 13² and 14²
Rational?
Irrational
Both square roots
±13.601471
Prime factorization
5 × 37
Cube root
5.698019

How to simplify √185

The prime factorization of 185 is 5 × 37. Every prime appears only once, so there is no pair to bring outside the radical — √185 is already in simplest form (a "square-free" radicand).

A whole number has a rational square root only when every prime in its factorization appears an even number of times. In 185, 5 and 37 appear an odd number of times, so √185 is irrational and 13.6014705087 is a rounded value.

Where √185 sits between perfect squares

169 = 13² and 196 = 14² are the nearest perfect squares, so √185 lies between 13 and 14. 185 is 16 above 169 and 11 below 196, so the root is closer to 14.

√185 ≈ 13 + (185 − 169) ÷ (196 − 169) = 13 + 16/27 ≈ 13.5926
  • Straight line between 169 and 196: 13.5926 (0.07% low)
  • Tangent from 13, i.e. 13 + 16 ÷ 26: 13.6154 (0.1% high)
  • Tangent from 14, i.e. 14 − 11 ÷ 28: 13.6071 (0.04% high)

For √185 the tangent at 14 wins, missing by only 0.0057. Tangent estimates shine when the number sits close to a perfect square — here 185 is just 11 below 196.

1313² = 1691414² = 196√185 ≈ 13.6015
√185 on a number line, with tenths marked between 13 and 14.

Finding √185 with the Babylonian method

This is Newton’s method applied to f(x) = x² − 185: following the tangent line down to zero simplifies to averaging x with 185 ÷ x.

xnext = (x + 185 ÷ x) ÷ 2

Start from the nearest whole number, 14 (14² = 196):

StepGuess x185 ÷ xAverageCorrect decimals
114.000000000013.214285714313.60714285712
213.607142857113.595800524913.60147169105
313.601471691013.601469326413.6014705087all 10 shown

The count of correct decimals went 2, 5 and all 10 over 3 steps — roughly doubling each time — until the guess matched √185 = 13.6014705087 to every decimal shown.

√185 as a continued fraction

Every irrational square root has a continued fraction that repeats. For √185 the pattern is [13; 1, 1, 1, 1, 26] with the block of 5 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √185 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
13/113.00000000006.0 × 10⁻¹
14/114.00000000004.0 × 10⁻¹
27/213.50000000001.0 × 10⁻¹
41/313.66666666676.5 × 10⁻²
68/513.60000000001.5 × 10⁻³
1,809/13313.60150375943.3 × 10⁻⁵

The same fractions solve Pell’s equation, x² − 185y² = 1. Its smallest solution in positive whole numbers is x = 9,249, y = 680. Because the period is odd, the equation with −1 on the right also has a solution: 68² − 185 × 5² = −1.

√185 in geometry and everyday measurements

  • A square room or garden bed covering 185 square feet measures about 13.6 ft (13 ft 7 in) along each wall.
  • 185 = 4² + 13² = 8² + 11², so by the Pythagorean theorem √185 is the diagonal of rectangles measuring 4 × 13 and 8 × 11 — and the distance between the points (0, 0) and (4, 13) on a grid.
RootSimplest formDecimalPerfect square?
√182√18213.4907No
√183√18313.5277No
√1842√4613.5647No
√185√18513.6015No
√186√18613.6382No
√187√18713.6748No
√1882√4713.7113No
  • The cube root of 185 is about 5.698019.
  • Four times the radicand doubles the root: √740 = 2 × √185 ≈ 27.202941.

Frequently asked questions

What is the square root of 185?

The square root of 185 is √185, about 13.6014705087. The negative root, −13.601471, also squares to 185.

Is the square root of 185 rational or irrational?

Irrational. 185 is not a perfect square — it falls between 169 and 196 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.

Can √185 be simplified?

No. 185 = 5 × 37 has no repeated prime factor, so there is no perfect square to take out of the radical.

What is √185 rounded to two decimal places?

√185 ≈ 13.60 to two decimal places (13.6 to one, 13.601 to three). Check: 13.60² = 184.96, close to 185.

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