There are 32 thousand people living in Kostomuksha. The town is situated on the longitude 64 degree North and 31 degree East. The total area of the towns region is 512 square kilometres. The area of the woods is 327,4 square kilometres, the water reservoir area is 53,9 square km. and the towns area itself is 41,5 square km. Distance to Finnish border is about 33 km.