Method for calibrating a measuring device for several products, comprising the following steps: - Measuring a set of measured values (X p ={x p i,j}) with several measured variables (j > 1), for several products (p) and with several measurements (i), - Providing of a set of reference variables (Y p ={y p i i-th reference variable}) with at least one reference variable to be determined by the measured variables (x P i,j), characterised by - Summarising the measured values ( X p) for all products into an extended data matrix of the measured values( X '), to which non-numerical, categorical variables are attached as dummy variables to differentiate between the measured values, - Determining a first set of calibration parameters ( C') from the measured values (X') of the data matrix, which has one or more weights( c j p) for one or more products (p), wherein the one or more products (p) are summarised within a product family which has an equal weight (c j) for at least its products, which is independent of the product, - Determining at least one further set of calibration parameters ( C") for a sub-matrix of the expanded data matrix of the measured values (X') for calibrating the measuring device, the non-numerical, categorical variables being assigned further weights of the further set of calibration parameters( C"), wherein ∘ one or more sets with further weights are determined within the first product family and several products (p) with the same weights( c j p) are combined to form a further product family, and ∘ outside the first product family, further sets with further weights are determined and several products (p') with the same weights( c j p ′) are combined to form a further product family, ∘ until all weights have been determined for the calibration of the measuring device - Measuring a set of measured values (X p ={x p i,j}) with several measured variables (j > 1), for several products (p) and with several measurements (i), - Providing of a set of reference variables (Y p ={y p i i-th reference variable}) with at least one reference variable to be determined by the measured variables (x P i,j), characterised by - Summarising the measured values ( X p) for all products into an extended data matrix of the measured values( X '), to which non-numerical, categorical variables are attached as dummy variables to differentiate between the measured values, - Determining a first set of calibration parameters ( C') from the measured values (X') of the data matrix, which has one or more weights( c j p) for one or more products (p), wherein the one or more products (p) are summarised within a product family which has an equal weight (c j) for at least its products, which is independent of the product, - Determining at least one further set of calibration parameters ( C") for a sub-matrix of the expanded data matrix of the measured values (X') for calibrating the measuring device, the non-numerical, categorical variables being assigned further weights of the further set of calibration parameters( C"), wherein ∘ one or more sets with further weights are determined within the first product family and several products (p) with the same weights( c j p) are combined to form a further product family, and ∘ outside the first product family, further sets with further weights are determined and several products (p') with the same weights( c j p ′) are combined to form a further product family, ∘ until all weights have been determined for the calibration of the measuring device ∘ one or more sets with further weights are determined within the first product family and several products (p) with the same weights( c j p) are combined to form a further product family, and ∘ outside the first product family, further sets with further weights are determined and several products (p') with the same weights( c j p ′) are combined to form a further product family, ∘ until all weights have been determined for the calibration of the measuring device