Abstract Innovative tools developed in education should be in line with the economic reality. The innovations of disadvantageous cost- to-benefits ratio could be interesting, but not sustainable in use for a long time. The paper provides a calculation scheme to measuring the efficiency of investments into such an innovation in education - knowledge texts. As other authors focus on the learning outcomes reached through the texts or time savings in a learning process, we are dealing with knowledge texts from the viewpoint of economic efficiency. General calculation scheme as well as the case study on its application is provided in the paper.