√165 ≈ 12.8452
√165 is an irrational number, so its decimals never end or repeat. It sits between 12 and 13 because 12² = 144 and 13² = 169.
| Decimal places | Value |
|---|---|
| 0 | 13 |
| 1 | 12.8 |
| 2 | 12.85 |
| 3 | 12.845 |
| 4 | 12.8452 |
| 5 | 12.84523 |
| 10 (digits) | 12.8452325787 |
165 has no perfect-square factor other than 1, so √165 is already in simplest radical form.
12.8452 × 12.8452 ≈ 164.9992, which is very close to 165.
Need another number? Use the square root calculator (also cube roots and other roots).
| Number | Square root |
|---|---|
| 161 | 12.6886 |
| 162 | 12.7279 |
| 163 | 12.7671 |
| 164 | 12.8062 |
| 166 | 12.8841 |
| 167 | 12.9228 |
| 168 | 12.9615 |
| 169 | 13 |