AbstractThis paper describes a procedure for the calculation of branch flows in a directed network in which the node‐to‐node flows are prescribed.The node‐to‐node paths of the network are enumerated using a combinatorial process. Procedures based on the path list are used to allocate the node‐to‐node flows to the alternative paths of the network according to Wardrop's first principle. The calculation, although necessarily iterative, is rapidly convergent.The method has been implemented as a computer program and the results obtained for a typical network are discussed.A linear relationship between branch potential and branch flow has been used, but the method can be extended to piece‐wise linear and non‐linea