How do generations work

Add your parent’s average age together and divide by 2. This is the average generation interval for your immediate family.

By simple mathematics, it follows that the human race is about 300 generations old. If one assumes a typical generation is about 20 years, this gives an age of about 6000 years. This calculation is done in the following way.

That is why the generations today each span 15 years with Generation Y (Millennials) born from 1980 to 1994; Generation Z from 1995 to 2009 and Generation Alpha from 2010 to 2024. So it follows that Generation Beta will be born from 2025 to 2039.

It is believed to have originated with the Iroquois – Great Law of the Iroquois – which holds appropriate to think seven generations ahead (about 140 years into the future) and decide whether the decisions they make today would benefit their children seven generations into the future.

A generation is “all of the people born and living at about the same time, regarded collectively.” It can also be described as, “the average period, generally considered to be about 20–⁠30 years, during which children are born and grow up, become adults, and begin to have children.”

Generally, three or four generations span 100 years, but depending on a number of factors, that same amount of time could produce as little as two generations or as many as five generations. The average span between one generation and the next is about 25 to 30 years, so a safe answer would be 75 to 90 years.