AbstractA new exponential‐hyperbolic size‐dependent crystal growth rate functionG (L)=Gm(eaL–b)/(eaL–c) is proposed. The model has been examined in detail for the direct determination of size‐dependent crystal growth rates from the cumulative number oversize distribution of continuous Mixed‐Suspension Mixed‐Product Removal (MSMPR) crystallizers using both simulated and realistic data, both for systems that hold and that violate McCabe's Δ law, respectively. It is show that direct fitting of cumulative number oversize distribution data using the proposed model gives an improved estimation of effective crystal growth rates over the whole size range during MSMPR crystallization compared with previous