Geodetic investments support in the scope of modernization the existing sections of railways and building new ones is associated with the work of high accuracy. For this reason, surveying teams use the latest technological solutions, both in terms of hardware and software. Among the rail surveying systems dedicated for railway areas, there are trolleys equipped with GNSS satellite receivers. Unfortunately, the GNSS system is not sufficiently accurate in determining the height of the railway track. Therefore, the surveying work is often broken down into two stages. In the situational surveys total stations or GNSS receivers are used, and in the surveys of height, geometric levelling is applied. The article describes the possibility of using an electronic level in order to eliminate cumbersome levelling surveys. A clinometer used in the surveys firstly had been subjected to author's laboratory tests verifying its accuracy and allowing its calibration. During the field tests, the selected section of the track was measured using a level, and additional standard surveys were carried out using geometric precision levelling. A computational method was also suggested, allowing for the determination of the heights of points, based on the measured slopes. The method is based on integrating a continuous model of slopes, interpolated by a set of polygonal chains. The study conducted accuracy tests both of the computational method itself as well as combined, survey and computational method for determining the height.