A practical method to calculate mass-attenuation coefficients of β particles has been described. This method is based upon the analytical conclusion of β emission energy spectrum and the range distribution of an individual β particles. The mass-attenuation coefficients are obtained as the slope of the semi-log plot of theoretical calculated fraction of transmission vs. the foil thicknesses. This method has been applied to obtain the mass-attenuation coefficients of β particles in aluminium, copper and gold. The results have been compared with the values given in previous works. © 2005 Elsevier Ltd. All rights reserved.