The article presents the result of investigations on length of hydraulic jump. Experiments were conducted on model of the weir with the outflow under the closure and with stilling basin, with additionally inserted baffle blocks in two different case settings. The length of the hydraulic jump was determined based on flow velocity measurements in the stilling basin. The measured lengths of hydraulic jump were compared with the other authors formulas and equations recommended for use in design practice. Obtained results demonstrated a large discrepancy in the length of the hydraulic jump calculated based on authors formulas or practical equations with comparison to measured ones. Experiments showed that the use of baffle blocks on the model, arranged in one row, has reduced the length of the hydraulic jump of 7–9%, and two rows of 15–19%. Practical benefit in the design of structures is possibility to shorten the stilling basin.