The distribution of income in an economy matters and can be measured on a country by country basis by the Gini Coefficient. However Gini values are not all up-to-date.
The World Economics Inequality Index is on a scale of 0-100, a high value indicates a more egalitarian society - and a low value suggests a lot of the national income is in the hands of very few depending upon the unit of measurement.
The table below shows the levels of inequality, ranked by least unequal to most unequal.
Data source: World Economics, London