Kastamonu's 2026 population is now estimated at 345,640. In 1927, the population of Kastamonu was 336,501. Kastamonu experienced a decrease of -17,721 residents over the past year, marking an annual decline of -4.88%. These population values and projections come from Turkey TUIK NIP population by sex and province time series and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Istanbul | 15,791,519 | 0.29% |
| Ankara | 5,956,929 | 0.79% |
| Izmir | 4,546,894 | 0.6% |
| Bursa | 3,315,749 | 1.18% |
| Antalya | 2,816,601 | 1.72% |
| Konya | 2,372,305 | 0.9% |
| Sanliurfa | 2,306,588 | 1.53% |
| Adana | 2,295,419 | 0.33% |
| Gaziantep | 2,242,869 | 1.12% |
| Kocaeli | 2,205,628 | 1.76% |
| Mersin | 2,002,110 | 1.22% |
| Diyarbakir | 1,863,340 | 0.81% |
| Hatay | 1,525,593 | -1.18% |
| Manisa | 1,490,486 | 0.51% |
| Kayseri | 1,470,263 | 0.61% |
| Samsun | 1,395,789 | 0.48% |
| Balikesir | 1,296,268 | 0.79% |
| Tekirdag | 1,245,788 | 2.44% |
| Aydin | 1,190,588 | 1.05% |
| Sakarya | 1,146,358 | 1.59% |
| Mugla | 1,125,767 | 2.01% |
| Kahramanmaras | 1,120,094 | -0.62% |
| Van | 1,108,489 | -0.43% |
| Denizli | 1,071,858 | 0.49% |
| Mardin | 919,553 | 1.31% |
| Afyonkarahisar | 758,932 | 0.58% |
| Erzurum | 738,409 | -0.44% |
| Ordu | 697,368 | -4.88% |
| Malatya | 679,072 | -4.88% |
| Batman | 673,642 | 1.45% |
| Elazig | 667,458 | 5.13% |
| Sivas | 638,849 | 0.14% |
| Kutahya | 631,139 | 5.13% |
| Tokat | 613,879 | 0.1% |
| Adiyaman | 602,261 | -0.72% |
| Sirnak | 589,833 | 1.65% |
| Zonguldak | 584,168 | -0.22% |
| Canakkale | 582,165 | 1.15% |
| Osmaniye | 569,580 | 0.76% |
| Giresun | 503,872 | 5.13% |
| Agri | 485,243 | -1.47% |
| Corum | 471,723 | -4.88% |
| Yozgat | 456,614 | 5.13% |
| Aksaray | 449,306 | 1.11% |
| Isparta | 448,450 | 0.23% |
| Edirne | 425,658 | 0.52% |
| Duzce | 421,079 | 1.05% |
| Kirklareli | 387,030 | 1.05% |
| Mus | 385,540 | -0.87% |
| Amasya | 378,386 | 5.13% |
| Siirt | 371,838 | 5.13% |
| Bitlis | 364,858 | 0.7% |
| Nevsehir | 351,391 | 5.13% |
| Rize | 349,022 | 0.29% |
| Kastamonu | 345,640 | -4.88% |
| Nigde | 337,240 | -4.88% |
| Bolu | 331,224 | 0.73% |
| Yalova | 325,124 | 2.76% |
| Bingol | 284,910 | 0.29% |
| Kirikkale | 284,340 | 0.23% |
| Hakkari | 283,581 | 0.25% |
| Burdur | 279,100 | 0.59% |
| Karabuk | 253,233 | 0.55% |
| Sinop | 250,826 | 5.13% |
| Kirsehir | 245,808 | 0.26% |
| Erzincan | 244,806 | 0.74% |
| Karaman | 237,783 | -4.88% |
| Bilecik | 232,837 | 0.95% |
| Bartin | 210,761 | 0.97% |
| Igdir | 210,526 | 0.88% |
| Cankiri | 203,431 | 0.86% |
| Kilis | 173,223 | 5.13% |
| Gumushane | 137,725 | -1.73% |
| Tunceli | 95,721 | 5.13% |
| Bayburt | 92,476 | 5.13% |
| Ardahan | 89,042 | -1.27% |
| Eskisehir | 83,393 | -4.88% |
| Trabzon | 74,402 | -4.88% |
| Usak | 33,959 | -4.88% |
| Artvin | 15,317 | -4.88% |
| Kars | 2,464 | -4.86% |
