Abstract: The generalized equation for calculation of the coefficient of hydraulic friction λ is introduced. Based on analyzing the current equations for calculation of the coefficient of friction and through a special intermediate function, a new generalized equation has been obtained. The author recommends a equation, , which can be used for the hydraulic calculation of actual pipeline. This equation covers the entire flow region, absolutely avoids the procedure to determine liquid flow region, is suited to any Reynold's number and relative roughness ε of pipe, and eliminates the inconsistency of λ in different boundaries of flow region due to its continuity.