Design of high-tech powertrains such as low cost, dense and high power transmission systems, need a precise computational modelling of compact gear drives and low-vibration gear systems. Compact gears achieved by minimising the clearance between gear teeth. For this aim, interference between a gear pair has to be avoided for a healthy gear system. The modelling of a gear pair without interference will be used for the analysis of low vibration gear systems. The main concern about low-vibration systems is how to tailor the whole stiffness of a gear pair for controlling the amount of vibration in the gear system. This object leads gear researchers to investigate the gear mesh compliance. This paper presents an analytical modelling framework for interference of a gear pair. Non-dimensionalisation methodology has been used to quantify the influence of design parameters of gear geometry on interference risk and the precision of gear mesh compliance. Combinations of analytical and numerical (finite element) method applied to formulate the function of gear mesh compliance base on the design parameters and the position of two mating gears along the line of action. The results of interference model and compliance function give us a powerful inverse solution as a design guideline for the design of high-tech powertrain regarding vibration and compactness.