In this article, a novel cutting force modelling approach is proposed by employing the specific cutting force and corresponding quantitative analysis on the dynamic cutting process in diamond turning so as to accurately represent the dynamic cutting behaviour including both amplitude and spatial aspects simultaneously. The specific cutting forces at the unit cutting length and area as the so-called amplitude aspect can provide insight into the micro cutting phenomena particularly in relation to the chip formation and size effects. The cutting forces are analysed against the dynamically varied cutting time interval, as the so-called spatial aspect using wavelet transform technique and standard deviation analysis can render their dynamic components to particularly represent dynamic effects of the cutting process and their correlation with tool wear. The cutting trials on titanium, silicon, and aluminium are carried out at a diamond turning test rig and supported with finite element analysis–based simulations, to further investigate the cutting force modelling and its correlation with the dynamic cutting process with a focus on the pressure distribution on the tool cutting edge, chip formation, and corresponding tool wear.