By considering railway track geometry as a fractal pattern, the irregularity of the track geometry can be expressed numerically with the help of fractal dimensions. In this study, a novel algorithm based on ruler method has been developed and a program was written to determine the fractal dimensions of railway track geometry graphs. Four different fractal dimensions of D(R)1, D(R)2, D(R)3, and D(R)4 were proposed to determine the geometric irregularity of the railway track by using the data of Ankara-Eskisehir High-Speed Railway track. D(R)1 and D(R)2 were used to quantify short wavelength irregularities while D(R)3 and D(R)4 were used to quantify medium wavelength irregularities. At the end of the study, the relationship between fractal dimensions and standard deviation values, which is the quality indicator according to EN 13848-6, was investigated. According to this, there is a strong relationship between the D(R)3 and the standard deviation. (C) 2020 Elsevier Ltd. All rights reserved.