A low-order dynamic model of a clutch for hydraulic control in an automatic transmission is developed by separating dynamics of the shift into four regions based on clutch piston position. The first three regions of the shift are captured by a physics-based model and the fourth region is represented by a system identification model. These models are determined using nominal values and validated against nominal and off-nominal experimental data. The model provides two lumped flow parameters to be used for tuning to the desired hydraulic clutch system.