GDP
The Byzantine GDP per capita has been estimated by the World Bank economist Branko Milanovic to range from $680 to $770 (in 1990 International Dollars) at its peak around 1000 AD (reign of Basil II). The Byzantine population size at the time is estimated to have been between 12 and 18 million. This would yield a total GDP somewhere between $8.16 and $13.86 billion.
Read more about this topic: Byzantine Economy