Estimates of the total Etruscan population are very difficult to establish since scholars have to identify household size and the number of households in any given city which can only be incompletely excavated. Estimates from tombs have to make assumptions about the inclusion of all the population among the formal burials. A further estimate has also to be made for the density of the occupation of the countryside. In South Etruria, Etruscan society was highly urbanized and centralized in the urban centers so the population estimates (between 25,000 and 15,000) for these cities give some sense of the scale of the whole population. These estimates agree broadly with those inferred from the most detailed excavation of any Etruscan city (at Acquarossa), from which a total urban population of 22,000 to 30,000 inhabitants can be estimated for the largest of the primary centers. In some cases such as the Albegna Valley, estimates can be made of the relative proportions for the urban versus rural populations even though this would have fluctuated through time. One estimate for this region is that as much as 70 percent of the population would have been in the urban center during the sixth century BC. Unfortunately, for the purposes of generalization, this particular region is located in a boundary area between major cities for much of its historical development, although in the sixth century BC it was probably more typical because it had a major city of its own, La Doganella.
Historical Dictionary of the Etruscans. Simon K. F. Stoddart.