Simulation of the milling process is a widespread method to improve productivity in the machining process and several phenomena can be studied and controlled by this mean. All these methods need input parameters that characterize the interaction between the tool and the workpiece in order to evaluate the cutting forces. Many models exist, but the input parameters are often difficult to find out from intrinsic properties of the materials (Young's modulus, yield strength, hardness, ...). The aim of this article is to set out a simple and efficient method to compute cutting coefficient for two different cutting forces models from a single efforts measurement. The method is validated using both simulated and measured cutting forces. The adequacy is good and allows simulating the whole cutting process.