Petrokerasa, known before 1927 as Ravna (Ραβνά), is a village and a community of the Lagkadas municipality. Before the 2011 local government reform it was part of the municipality of Kallindoia, of which it was a municipal district. The 2021 census recorded 250 inhabitants in the village. The community of Petrokerasa covers an area of 27.398 km2.