Trying to find solution

I am trying to set a SharePoint list that has workplans for example:

1.1 Workplan A (only has 1 sub component 1.1.1)

1.2 Workplan B (but workplan B has 3 sub components 1.2.1 - 1.2.2 - 1.2.3)

1.3 Workplan C (but workplan C has 5 sub components 1.3.1 - 1.3.2 - 1.3.3 - 1.3.4 - 1.3.5)

My goal is, I can do a percent complete on each sub component (that is a manual entry by the user)

I want to be able to take the sub components and do an average of each workplan to see how much has been completed (%) in each of the Workplans.

for example:

workplan B - sub components 1.2.1 = 50%

                                                 1.2.2 = 20%

                                                 1.2.3 = 35%

Total workplan B % = 35%  (sub 1 + sub 2 + sub 3 = 105 / 3 = 35%)

I tried Calculated columns but they will only work on the same row.

Anyone out there that can help it would be really appreciated.

I have columns setup for WorkPlan, Subcomponent, subcomponent %, and Workplan %