I divided the thesis into two main parts: theoretical and practical. In the theoretical part, I analyze possibilities of legal tax optimization. The practical part was prepared on an example of an entrepreneur, whose income comes not only from his business activity, but also from lease and other sources. He lives in a household with a wife and a daughter. In the practical part, I calculate the total tax duty of the household, but also social and health insurance duty, the amount of which also depends on the tax base. In the practical part, I found six models of tax calculation for this particular household.