Qal'achai Kalon or Kalachai-Kalon (Russian: Калачаи-Калон; Tajik: Қалъачаи Калон), formerly known as Pravda (Tajik: Правда), is a village and jamoat in north-western Tajikistan. It is part of the city of Istaravshan in Sughd Region. The jamoat has a total population of 15,433 (2015).