We present experimental high-field magnetization studies for the single-crystalline ferrimagnetic RFe11Ti compounds at example of holmium-based hydride in order to evaluate, compare and analyze the crystal-field and exchange parameters. We predict theoretically the magnetization behavior of HoFe11Ti up to 80 T magnetic field for the first time. The results are compared with data for the parent compound HoFe11TiH1 and those with erbium and thulium (x = 0 and 1).