The paper is focused on the phenomenon of tax evasion, its effects and ways of sizing it. The objective includes a fundamental theoretical analysis study of the methodological part focused on the indicator of fiscal pressure. In the work, the authors presented the causal links between taxation, fiscal pressure and fiscal evasion, how these phenomena are measured at the macro and micro economic level. Studying the causes and effects of tax evasion manifested at the country and organization/entity level, the researchers mentioned the financial position, financial performance and cash flows as elements to reduce tax fraud. For this, different formulas for calculating tax pressure and tax evasion have been established, presented and systematized to reduce tax pressure through the financial performance of the entity.