[en] Determination of absorbed dose in biological targets after high LET α particles irradiation needs heavy calculations. A software has been developed in order to allow everyone to calculate hit probability and absorbed dose. It is particularly adapted to the study of cell cultures irradiated with electrodeposited source or α -beam accelerator. It is based first, on a random generator of α -track homogeneously distributed in 47π, second, on the evaluation of energy loss in the different media along the track and then on a statistical analysis of the results. This method is accurate and low time consuming. The target is either modeled by an ellipsoid or represented by its 3-D shape recorded using confocal microscopy. (authors)