√223 at a glance
- Exact value
- √223
- Decimal (10 places)
- 14.9331845231
- Rounded
- 14.9 · 14.93 · 14.933
- Perfect square?
- No — between 14² and 15²
- Rational?
- Irrational
- Both square roots
- ±14.933185
- Prime factorization
- 223
- Cube root
- 6.064127
How to simplify √223
223 is a prime number, so its only factors are 1 and 223. There is no perfect-square factor to pull out, which means √223 is already in its simplest radical form.
The square root of any prime is irrational. If √223 were a fraction a/b in lowest terms, then a² = 223b², so 223 would divide a — and then 223 would divide b too, contradicting “lowest terms.” That is why the decimal 14.9331845231 is only a rounded value.
Where √223 sits between perfect squares
196 = 14² and 225 = 15² are the nearest perfect squares, so √223 lies between 14 and 15. 223 is 27 above 196 and 2 below 225, so the root is closer to 15.
- Straight line between 196 and 225: 14.9310 (0.01% low)
- Tangent from 14, i.e. 14 + 27 ÷ 28: 14.9643 (0.21% high)
- Tangent from 15, i.e. 15 − 2 ÷ 30: 14.9333 (0% high)
For √223 the tangent at 15 wins, missing by only 0.0001. Tangent estimates shine when the number sits close to a perfect square — here 223 is just 2 below 225.
Finding √223 with the Babylonian method
If a guess is too big, 223 ÷ 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√223) in one step.
Start from the nearest whole number, 15 (15² = 225):
| Step | Guess x | 223 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 15.0000000000 | 14.8666666667 | 14.9333333333 | 3 |
| 2 | 14.9333333333 | 14.9330357143 | 14.9331845238 | 9 |
| 3 | 14.9331845238 | 14.9331845223 | 14.9331845231 | 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 √223 = 14.9331845231 to every decimal shown.
√223 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √223 the pattern is [14; 1, 13, 1, 28] with the block of 4 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √223 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 |
|---|---|---|
| 14/1 | 14.0000000000 | 9.3 × 10⁻¹ |
| 15/1 | 15.0000000000 | 6.7 × 10⁻² |
| 209/14 | 14.9285714286 | 4.6 × 10⁻³ |
| 224/15 | 14.9333333333 | 1.5 × 10⁻⁴ |
| 6,481/434 | 14.9331797235 | 4.8 × 10⁻⁶ |
| 6,705/449 | 14.9331848552 | 3.3 × 10⁻⁷ |
The same fractions solve Pell’s equation, x² − 223y² = 1. Its smallest solution in positive whole numbers is x = 224, y = 15.
√223 in geometry and everyday measurements
- A square patio or deck of 223 square feet is about 14.93 ft (14 ft 11 in) on each side, so edging all the way around takes 4 × √223 ≈ 59.7 ft.
- 223 is not a sum of two whole-number squares — 223 is itself a prime that is one less than a multiple of 4, which rules that out — so √223 is never the diagonal of a rectangle with whole-number sides. It is not a sum of three positive squares either, so no whole-number box has √223 as its space diagonal.
Square roots near √223 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √220 | 2√55 | 14.8324 | No |
| √221 | √221 | 14.8661 | No |
| √222 | √222 | 14.8997 | No |
| √223 | √223 | 14.9332 | No |
| √224 | 4√14 | 14.9666 | No |
| √225 | 15 | 15.0000 | Yes |
| √226 | √226 | 15.0333 | No |
- The cube root of 223 is about 6.064127.
- Four times the radicand doubles the root: √892 = 2 × √223 ≈ 29.866369.
Frequently asked questions
What is the square root of 223?
The square root of 223 is √223, about 14.9331845231. The negative root, −14.933185, also squares to 223.
Is the square root of 223 rational or irrational?
Irrational. 223 is not a perfect square — it falls between 196 and 225 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √223 be simplified?
No. 223 is prime, so there is no perfect square to take out of the radical.
What is √223 rounded to two decimal places?
√223 ≈ 14.93 to two decimal places (14.9 to one, 14.933 to three). Check: 14.93² = 222.9049, close to 223.