Square Root of 16
The square root of 16 is exactly 4. Yes, 16 is a perfect square. Its square root, 4, is a whole number.
Where √16 sits
16 is a perfect square: 4 × 4 = 16, so √16 is exactly 4. No estimating needed.
| k | k² | Compared to 16 |
|---|---|---|
| 2 | 4 | 12 below |
| 3 | 9 | 7 below |
| 4 | 16 | equal |
| 5 | 25 | 9 above |
| 6 | 36 | 20 above |
| 7 | 49 | 33 above |
Exact form from the prime factors
16 = 2^4. Every prime appears an even number of times, so the whole thing comes out of the square root: √16 = 4.
Frequently Asked Questions
What is the square root of 16?
The square root of 16 is exactly 4.
Is 16 a perfect square?
Yes, 16 is a perfect square. Its square root, 4, is a whole number.
What two whole numbers is √16 between?
None needed -- √16 is exactly 4, a whole number. For context, the perfect squares just before and after 16 are 9 (3²) and 25 (5²).
What are the square roots of the numbers right next to 16?
√15 is about 3.873, and √17 is about 4.1231. Square roots increase more slowly as the number gets bigger, which is why consecutive whole numbers have roots that get closer together the higher you go.
What is √16 squared?
Exactly 16 -- squaring undoes the square root. Squaring the rounded decimal 4 gives 16, which is why the radical form 4 is the exact answer and the decimal is an approximation.
What is the negative square root of 16?
−4. Every positive number has two square roots, one positive and one negative, because (−4)² is also 16. The radical sign √ by convention means the positive one.
More Number Theory
- Square Root Calculator (look up any number)
- Factors of 16
- GCF Calculator
- LCM Calculator