The aim of this study was to design a formula to evaluate the jumping ability of young mares on the basis of an analysis of the correlation between the judge rating and parameters of the length and the height of the jump. The material consisted of recordings of 30 free jumping mares representing Polish Warmblood and Halfbred Angloarab breeds, which were subjected to the performance test (60-day test). Each mare jumped over an oxer, with a successively increased height. Notes given by the judge included the jump length, jump height, courage and the willingness to jump. In MultiScanBase software measurements were also made which were determined by the length of jump stride, length of jump suspension, distance between the sternum and the pole of the second part of the obstacle. The statistical analysis was performed by PQStat softwere, while differences between the means were verified by T-Tukey test. To design a formula of a measurable method of jumping ability Pearson correlation coefficients were used. The results indicate that the evaluation of the jumping ability of young mares with measurable traits should be conducted on an obstacle of a minimum 115 cm in height. A high variation of the length of the jump stride, length of jump suspension, distance beetwen the sternum and the pole, offers the opportunity to use the trait as a selection criterion. A formula designed in this paper can be helpful to complement and objectify the system of testing mares in training centers.