Commonly used fatigue crack growth prediction models estimate life in a deterministic manner. Realizing that several variables influence fatigue crack growth, it is pertinent to assess crack growth using probabilistic models. In the present work, a probabilistic model is studied using continuous and segmented crack growth rate data models. It is observed that the prediction of life using Paris constants from continuous data model is accurate only in a finite region of the crack growth. The model based on segmented data provides more accurate life predictions with lesser variance with experimental data than the continuous data model. © 2011 Elsevier Ltd. All rights reserved.