When archaeologists deal with prehistoric sites (such as Troy I -VII) they must rely on statistical methods to figure out things like population size. That is because there are no written sources.

Troy II, for example, covered an area of 90,000 square meters (about 22 acres). From other Early Bronze Age settlements, we know there were 150 people per acre (this is called the population density). We can then calculate the population:

22 acres x 150 people/acre = 3300 people.

Another technique is to look at the amount of land available for growing crops. If Troy II had 4700 acres of land available, and the food from this kind of farming can support 0.6 people per acre, then we can estimate the population with this calculation:

4700 acres x 0.6 people/acre = 2820 people

Because we are a little uncertain, we can take an average as our result:

(3300 + 2820) / 2 = 3060 (average population)

Troy VI had an area of about 250,000 square meters, or 62 acres. Could a larger population of, say, 10,000 people have been supported? The sea had receded quite a bit from the times of Troy II, so perhaps there was more farmland. But not so much as to triple the population. Were there innovations (such as the horse) that made the land more productive? These are the kinds of questions that archaeologists ask.