√227 at a glance
- Exact value
- √227
- Decimal (10 places)
- 15.0665191733
- Rounded
- 15.1 · 15.07 · 15.067
- Perfect square?
- No — between 15² and 16²
- Rational?
- Irrational
- Both square roots
- ±15.066519
- Prime factorization
- 227
- Cube root
- 6.100170
How to simplify √227
227 is a prime number, so its only factors are 1 and 227. There is no perfect-square factor to pull out, which means √227 is already in its simplest radical form.
The square root of any prime is irrational. If √227 were a fraction a/b in lowest terms, then a² = 227b², so 227 would divide a — and then 227 would divide b too, contradicting “lowest terms.” That is why the decimal 15.0665191733 is only a rounded value.
Where √227 sits between perfect squares
225 = 15² and 256 = 16² are the nearest perfect squares, so √227 lies between 15 and 16. 227 is 2 above 225 and 29 below 256, so the root is closer to 15.
- Straight line between 225 and 256: 15.0645 (0.01% low)
- Tangent from 15, i.e. 15 + 2 ÷ 30: 15.0667 (0% high)
- Tangent from 16, i.e. 16 − 29 ÷ 32: 15.0938 (0.18% high)
For √227 the tangent at 15 wins, missing by only 0.0001. Tangent estimates shine when the number sits close to a perfect square — here 227 is just 2 above 225.
Finding √227 with the Babylonian method
If a guess is too big, 227 ÷ x is too small by about the same amount, so their average lands much closer. In fact an error of e shrinks to roughly e² ÷ (2√227) in one step.
Start from the nearest whole number, 15 (15² = 225):
| Step | Guess x | 227 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 15.0000000000 | 15.1333333333 | 15.0666666667 | 3 |
| 2 | 15.0666666667 | 15.0663716814 | 15.0665191740 | 9 |
| 3 | 15.0665191740 | 15.0665191726 | 15.0665191733 | all 10 shown |
The count of correct decimals went 3, 9 and all 10 over 3 steps — roughly doubling each time — until the guess matched √227 = 15.0665191733 to every decimal shown.
√227 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √227 the pattern is [15; 15, 30] with the block of 2 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √227 is irrational.
Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:
| Fraction | Decimal | Error |
|---|---|---|
| 15/1 | 15.0000000000 | 6.7 × 10⁻² |
| 226/15 | 15.0666666667 | 1.5 × 10⁻⁴ |
| 6,795/451 | 15.0665188470 | 3.3 × 10⁻⁷ |
| 102,151/6,780 | 15.0665191740 | 7.2 × 10⁻¹⁰ |
| 3,071,325/203,851 | 15.0665191733 | < 10⁻¹⁰ |
| 46,172,026/3,064,545 | 15.0665191733 | < 10⁻¹⁰ |
The same fractions solve Pell’s equation, x² − 227y² = 1. Its smallest solution in positive whole numbers is x = 226, y = 15.
√227 in geometry and everyday measurements
- A square patio or deck of 227 square feet is about 15.07 ft (15 ft 1 in) on each side, so edging all the way around takes 4 × √227 ≈ 60.3 ft.
- 227 is not a sum of two whole-number squares — 227 is itself a prime that is one less than a multiple of 4, which rules that out — so √227 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 1 × 1 × 15 box, because 1² + 1² + 15² = 227.
Square roots near √227 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √224 | 4√14 | 14.9666 | No |
| √225 | 15 | 15.0000 | Yes |
| √226 | √226 | 15.0333 | No |
| √227 | √227 | 15.0665 | No |
| √228 | 2√57 | 15.0997 | No |
| √229 | √229 | 15.1327 | No |
| √230 | √230 | 15.1658 | No |
- The cube root of 227 is about 6.100170.
- Four times the radicand doubles the root: √908 = 2 × √227 ≈ 30.133038.
Frequently asked questions
What is the square root of 227?
The square root of 227 is √227, about 15.0665191733. The negative root, −15.066519, also squares to 227.
Is the square root of 227 rational or irrational?
Irrational. 227 is not a perfect square — it falls between 225 and 256 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √227 be simplified?
No. 227 is prime, so there is no perfect square to take out of the radical.
What is √227 rounded to two decimal places?
√227 ≈ 15.07 to two decimal places (15.1 to one, 15.067 to three). Check: 15.07² = 227.1049, close to 227.