Hatvan's 2026 population is now estimated at 19,346. In 1980, the population of Hatvan was 23,981. Hatvan experienced a decrease of -159 residents over the past year, marking an annual decline of -0.82%. These population values and projections come from Hungary historical city/town census values 1980 and 1990 via CityPopulation fallback access, Hungary Census 2022 API (WBS003) settlement population (2001, 2011, 2022), Hungary city/town 2025 official estimate via CityPopulation fallback access and World Population Review Internal Projections .