For those interested: One thing that always annoyed me in Civ 5 was that I could never see what the world's total population was during or after a game (along with a game replay etc). So I went and created a scenario with one city surrounded by rivers and wheat-farms to see what the demographics screen said was my actual population at each city population/size level (1, 2, 14 etc). This is the data I got: The Data will be presented as: City Size. Actual Population I stopped after my city grew to size 40 because seriously who can grow a city that large? TL;DR: here are the actual statistics (ala the demographics screen) for one city as it grows from size 1 to 40. Spoiler Actual city populations at certain city sizes : 1,000 6,000 21,000 48,000 90,000 150,000 232,000 337,000 469,000 630,000 823,000 1,051,000 1,315,000 1,618,000 1,963,000 2,352,000 2,787,000 3,271,000 3,806,000 4,394,000 5,037,000 5,738,000 6,498,000 7,321,000 8,207,000 9,160,000 10,181,000 11,273,000 12,436,000 13,675,000 14,990,000 16,383,000 17,858,000 19,415,000 21,056,000 22,784,000 24,601,000 26,509,000 28,508,000 30,603,000 The latest patch helped a lot with having more realistic total world populations - although to actually figure that out you would have to scrolls across the map recording each city's size and then cross reference it with this information before finally adding all the figures together. My guess is a huge size world at 4 billion years with medium rainfall and a temperate climate would be the most accurate to today's world size, Pangaea with a low sea level might create large total populations as well. My current game is a huge continents (3 billion years) on prince, 22 civs playing as Songhai and funnily enough Polynesia (who started on a lone island in what is probably the equivalent of the Pacific lol) have the largest city at size 30 and largest total population even though they only have 4 cities.