The topic of this thesis is the Ball-on-3-Balls test applied to discs and rectangular plates made of dental ceramics. The goal was to prepare a fitted formula for the biaxial stress distribution in samples of a given range of sizes. A program was also developed to calculate the effective Volume and Surface of these samples.Stress values were calculated through Finite Element Analysis and an empirical formula for the maximum stress under the loading ball was fitted to them. This formula is dependent on the sample's material properties and geometry in relation to the size of the balls used. A simplification of the stress formula for plate geometries to an effective disc radius was proposed. The effective volume and surface for a given sample can be interpolated from the numerical data. Further studies were done concerning the limits of the B3B test towards materials with extremely low Young's Modulus.