13 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 03246 | Laconia | 17,103 |
| 03249 | Gilford | 7,830 |
| 03220 | Belmont | 7,393 |
| 03253 | Meredith | 6,707 |
| 03225 | Center Barnstead | 3,834 |
| 03809 | Alton | 3,680 |
| 03269 | Sanbornton | 3,066 |
| 03237 | Gilmanton | 2,575 |
| 03256 | New Hampton | 2,497 |
| 03810 | Alton Bay | 2,314 |
| 03837 | Gilmanton Iron Works | 1,451 |
| 03218 | Barnstead | 1,160 |
| 03226 | Center Harbor | 1,005 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 13 ZCTAs in Belknap County, New Hampshire (US Census).