We have developed a simple and accurate method for calculating the equivalent density of wellbore collapse pressure in shale formations, which can be used for well path optimization. The calculation takes into account in-situ stresses, occurrence of bedding planes (direction, dip), the strength of bedding planes, rock strength, wellbore trajectory (deviation, azimuth), and also the external stress caused by mud filtrate invasion. We consider the influence of bedding planes on the equivalent density.