A 4 generation ancestor chart shows ancestors up to the fourth generation. Normally, this chart has the young ones at the bottom and the ancestors branching upwards.
When we talk of ancestors, we refer to every individual who has a descendant. Therefore, in a 4 generation ancestor chart, the great-grandparents make the ancestors in the entire pedigree. Most basic 4 generation ancestor charts have 8 great grandparents to represent grandparents from both the dad’s and the mom’s sides.
Moreover, individuals in the second and third generations are considered ancestors since they also have descendants. Simply put, a 4 generation ancestor chart has 8 ancestors and 14 ancestors in total.