Automatic Goal Seek

You have not given us any specifics to go on, and I potentially see a few different ways to approach this.

I proposed something very similar to your description here https://www.excelforum.com/excel-pro...ml#post4239530 We got as far as getting a working VBA procedure that could run Goal Seek on several cells in a loop. I don't know if the OP decided to put it in a change/calculate event procedure, but that should be straightforward if you have some understanding of event procedures: http://www.cpearson.com/Excel/Events.aspx