Square Root Calculator › Square root of 18
Square Root of 18
√18 ≈ 4.242641
18 is not a perfect square, so √18 is an irrational number that is approximately 4.242641. In simplified radical form, √18 = 3√2.
√18 lies between √16 = 4 and √25 = 5.
| Number | 18 |
| Square root (decimal) | 4.242641 |
| Simplified radical | 3√2 |
| Perfect square? | No |
| Rational? | No |
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Frequently asked questions
Is 18 a perfect square?
No, 18 is not a perfect square, so its square root is irrational and approximately 4.242641.
What is the square root of 18 in simplest radical form?
√18 = 3√2 in simplest radical form.