The paper answers one of the typical problems of economic theory - how it is in practice possible to measure and to interpret the quality of economic time series oat all economic levels. The task is on the macroeconomic level solved by weighted geometric aggregation of input factors (labour and capital) into summary input factor (SIF) - the method is similar to the Cobb-Douglas production function. The paper shows differences of our approach to the approach of growth accounting – our approach is based on more general condition and covers not only situations of growth of economic indicators but also situations of their falls or stagnation. The approach allows also distinguishing the compensation of input factors. So, the methodology presented in the paper can be used in many practical applications, for instance it enables us to count clearly intensive and extensive parameters of economic growth.