The work is aimed at the development of methods for predicting fatigue resistance and enhancing the reliability of elements of metal structures of machines. A methodology for calculating the rate of fatigue crack development under the action of cyclic loading is proposed. At present, the main methodological approach to solving this problem is based on the use of the Paris equation, the parameters of which are determined experimentally. This paper illustrates the advantage of transitioning to the use of the modified Paris equation and proposes a technique for analytical determination of its parameter. The proposed method is based on the assumption of discrete fatigue crack development and calculation of the number of cycles required for each jump using the Coffin-Manson equation. The validity of the proposed methodology is confirmed by a comparison of the results with an array of experimental data.