In industrial and economic geography, an isodapane is a line of equal additional transportation cost. Isodapanes are a theoretical tool used to assist in finding the optimal location for industry. They are a type of geographical contour line. The concept was introduced by Alfred Weber.
A series of isodapanes (points of equal transportation cost) are placed around the minimum cost point, with the curve farthest away from the minimum isodapane representing sites having the highest costs.