What is the duration of your period based on?

How much blood you have to bleed or do you just bleed for a set amount of days?|||the average ammount to bleed is about a cupful, but the duration varies for everybody, some peoples are 3 days, some peoples are 2 weeks, there is no real way of working it out, all you can do is see what you get.|||It's different for each person. There is an average, but it's just that. Everyone's body is unique and how it functions can be unique. There will be variations from person to person. There's nothing wrong with that.|||On average a woman's menstrual cycle is 28 days- with 7 days of actual bleeding. As far as how much bleeding on average it's about 50-100ml of blood loss. But as i said that's the average. Not all women are the same- some have lighter periods and some have heavier periods. Also some cycles are not based on a 28 day cycle, such as mine, which usually is on a 34-37 day cycle with only 5 days of actual bleeding. Hope I helped.