The paper reported using a mathematical model that simulated the wear volume in comparison to measurement by a ball-on-disc for deposited CrN films on tool steel (JIS SKD11). Three dimensional profile instruments were used to measure the wear scar trace for variations of numerical data of two dimensional profiles. By using numerical algorithms, the wear volume measurements of wear profiles are to save considerable time and economical. A new mathematical method is issued for determining wear volumes in this study. The estimated results were precisely fitted as compared with other calculations for three dimensional estimations of wear volumes.