On the basis of provided data from Slovak Hydrometeorlogical Institute were realized the calculation of rain factor for each rain-guage stations. Because provided data were in digital form, we proceeded to digital processing in graphical environment of Microsoft Excel i.e. each minutes of chosen rain were considered for separate rain division. Calculated data were compared with published values of Soil Science and Conservation Research Institute (SSCRI) and also with Methodology for implementation of research results into agricultural practise. From calculated values were created also the lines of exceedance of probability, which give detail information about occurrence of calculated values of rain factor once per 100, 50, 20, 10, 5 and 1 year. Also there were compared the different methodologies of rain factor calculation and kinetic energy of rain and their influence on final values. From calculated values there were found out that on all examined localities are our calculated values several times higher than in listed publications. These differences can be caused by different methods of data processing but also by number of processed years, because values of rain factor in listed publication were calculated for lower number of years. According to calculated values were created the redistribution of rain factor values on particular months of vegetation periods and it was found out that the highest percentage fall on summer months (June, July, August) and on the other hand, the lowest percentage, on the months April and October, therefore it is necessary to attach importance on soil erosion control especially in summer months. Comparison of different methods of data processing (digital vs. graphical) showed up, that differences in final values of rain factor by using of different methods of data processing are minimal, therefore it can be assumed that used methodology is right. Relations for kinetic energy calculation and different methodologies also significantly influenced final values of rain factor. Calculation of rain according different authors showed up that using relation for kinetic energy designed by Marshall, were obtained lower values, which influenced the final value of rain factor i.e. its final values was more closer to pu blished values. Comparison of Hudson (KE > 1) and Wischmeier and Smith methodology it was found out that with using Hudson methodology is final value of rain factor almost two times lower than with using Wischmeier and Smith methodology. It was also done the calculations of rain factor which take into account the lack of data. There were used the relations according different authors. These relations calculate only with annual precipitation. The results showed that final values of rain factor is several time higher than with using equations for example of Wischmeier and Smith.