To determine the coefficients for the calculation of pig live weights on the basis of their carcass weights, a representative group of totally 319 pigs was analysed. The coefficients were determined for both cold and hot carcass weights. The equation for calculating live weight (y) based on the cold carcass weight was as follows: y = 1.30*x. The equation for calculating live weight (y) based on the hot carcass weight was as follows: y = 1.27*x. The coefficients for different weight categories and genders were also determined. For practical use it is recommended to employ the cold carcass weight and the coefficient 1.30, as the cold carcass weight is compulsorily given in classification reports according to the Regulation MZe 324/2005.