Equilibrium swelling data with a range of solvents for non-filled cured rubber samples were used to determine Hansen three-dimensional solubility parameters (HSPs) of seven HNBR grades with nominal acrylonitrile contents from 21 to 49 % using the HSPiP computer program. The results showed that the increase of acrylonitrile contents for HNBR grades led to increase of polar component ( δ p ) and hydrogen bonding component ( δ h ), but with little changes of dispersion component ( δ d ). By using the so far obtained HSPs it is possible to explain and predict the swelling behaviors of the fully formulated HNBR-based vulcanizates in industrial oils (IRM 903 was selected for testing), in a reference bio-fuel (Fuel C was selected for testing) and in bio-diesel (FAME was selected for testing). In these liquids, the volume swellings decreased with increasing of Ra values (calculated by HSPs), and to a certain extent, can be calculated with a modified Flory–Rehner equation by assuming that fillers would not swell in question.