The demographics of the Ottoman Empire include population density, ethnicity, education level, religious affiliations and other aspects of the population.
Lucy Mary Jane Garnett stated in the 1904 book Turkish Life in Town and Country, published in 1904, that "No country in the world, perhaps, contains a population so heterogeneous as that of Turkey."
Demographic data for most of the history of the Ottoman Empire is not quite precise. For most of the five centuries of its existence, the empire did not have easily computable valid data except figures for the number of employed citizens. Until the first official census (1881–1893), data was derived from extending the taxation values to the total population. Because of the use of taxation data to infer population size, detailed data for numerous Ottoman urban centers - towns with more than 5,000 inhabitants - is accurate. This data was collaborated with data on wages and prices. Another source was used for the numbers