How long is a marathon game in civilization?

A marathon game of Civilization can depend. Mine usually takes about 3 weeks to complete but a lot goes into factoring the exact amount of time. You will have to take time out to do things like shower, eat, and even to sleep. Each era in the marathon version is the length of time as a single game is so you can just imagine how long it can go on. It can be painfully slow.

The average is probably about 300 turns per era and the total amount is about 1500 turns. How long it takes to play those turns can vary greatly according to who you are playing and how often you are playing and the pace you are playing at. If you are going to play a marathon, you'd better set aside a good long time to play and that's for sure and for certain. You don't want to get it started and then not follow through with it.