The thesis provides methodologies for determining railway structure gauge and distance between track centres. The first part provides information about reference profile, which is base for determining structure gauge. This is followed by description of different types of gauges, related to railway transport. The thesis also presents separation of railways according to number of tracks. The second part is based on Slovenian standard SIST EN 15273-3:2013. It describes methods for determining structure gauge including all presented widenings (additional overthrows, quasi static effect and random transverse phenomena). In accordance with same standard there are presented methods for determining distance between track centres. The last part of the thesis discusses differences between standard and UIC code 505-4 OR. Calculation examples of different railway gauges and distances between track centres are also included.