The invention relates to a method for ascertaining a net weight of a product in a product range, plurality of contiguous product ranges form a product chain and a total weight of the product chain is ascertained. The product chain is X-rayed to ascertain values that correspond to the radiation that penetrates a defined range of the product chain. The ascertained values are used to ascertain a total value for the entire product chain. A product range with a single product is selected by means of evaluation of the ascertained values. A value of the product range is formed from the ascertained values. A gross weight of the product range is ascertained therefrom. The net weight used for the single product is approximately the weight or the net weight is ascertained from the difference between the weight and a prescribed or ascertained weight of the product range without a product.