On the phase of dimensioning of the gear transmitters have influence center distance, gear ratio, material, thermal processing etc. The purpose of this paper is analysis of factors that have influence on the optimization of cylindrical gear transmitters. It is analyzed safety factor for pitting and safety factor for bending for gear transmitters on the dependence of center distance and gear ratio, than it is analyzed safety factor for pitting on dependence on safety factor for bending, gear
ratio and material.