The degree of contraction of jets issuing from conduits depends upon the geometry of the approach flow, particularly upon (1) the angle of convergence of the walls and (2) the ratio of the area of the jet opening to that of the approach flow. The work of Von Mises, which provided coefficients of contraction for the convergence angles that are multiples of π/4, has been extended to include all multiples of π/12. The analysis of the two-dimensional, irrotational flow is based on the classical free-streamline technique of Helmoltz and Kirchoff. Plots of the tabulated values ofCcfor the various angles and area ratios illustrate the trends and assist with interpolations. The computed coefficients have applications, to a useful approximation, to a wide variety of flows encountered in practice, including flows that are neither two-dimensional nor entirely free from effects of viscosity. Among them are flow through valves and gates in conduits and flow under floating bridges.