The main purpose of this paper is to discuss some of the measurement problems in connection with the perpetual inventory method applied for estimates of capital stock. In the Federal Republic of Germany, highly aggregated capital stock data by business sector are compiled by the Federal Statistical Office within its national accounts calculations, while more detailed capital stock estimates by industrial sectors are published by the German Institute of Economic Research (DIW) in Berlin. Because of various gaps in the statistical sources, the accuracy of the capital stock calculations is not yet entirely satisfactory. Aside from the problem of establishing long time series for gross fixed capital formation in constant prices for all sectors, it is difficult to obtain reliable data on the inter‐sectoral transactions in secondhand capital goods. In addition, there are problems of determining price indices and service life distributions of the fixed assets in the various parts of the economy. This paper shows a way to arrive at a reasonably close approximation to the latter proble