It is calculated by dividing nominal income by the price level.
Real variables such as real income and real GDP are variables that are measured in physical units, while nominal variables such as nominal income and nominal GDP are measured in monetary units.
Growth of real income is related to real gross national income per capita growth.
In other words, if the nominal starting income was 100 and there was 10% inflation (general rise in prices, for example, what cost 10 now costs 11), then with nominal income of still 100, one can buy roughly 9% less; so if nominal income was not adjusted for inflation (did not rise by 10%), real income has dropped by approximately 9%.
The real gross national income (GNI) per capita in constant 2015 USD according to the World Bank is shown for last available year:[2]