Research on the current state of Russian society indicates that many of the issues that Russians consider to be of practical importance focus on the single and most painful point: critical income inequality of extreme decile strata; this inequality significantly exceeds the norms that Russians can accept; it is perceived as unfair and poses threats to Russia’s integrity. To elaborate on the content of this important aspect, the authors focused on the role of income weights of the main macrostrata of the population, proposed for their measurement a new toolkit – a set of centile coefficients reflecting the inequalities of income weights of the macrostrata – and obtained quantitative values for these coefficients for all Russian regions. The results show that extreme inequality (about 15 times) continues to grow in the majority of Russian regions and is represented differentially in their contrasting clusters. In addition to the proposed author’s tools, the results of calculations presented in the article showed that extreme inequalities continue to grow in most Russian regions. Taking into account the absolute values and dynamics of inequality coefficients, 4 clusters were identified, uniting all subjects of the Russian Federation. It was established that the problem of inequality has a significant correlation with the type of territories modernization.