Calculations leading to the following recommendations for TL age estimations using (Th + U) gross alpha count rates (under secular equilibrium): the dose rate conversion factors to be used for alpha, beta, and gamma components of (Th + U) present in pottery are respectively 500.6, 23.0 and 27.5 mrad. yr to the minus one power per alpha emitter per cm squared/hr. Error component is also given.