There is a relatively new article on Financial Planning blog Kitces.com on trying to help clients understand about saving enough for a Coast FIRE lifestyle. Think it is a pretty good article and brings up some Coast FI planning points to think about. I would like to share what I think. On How They Calculate the Coast FIRE Number The article says that to compute your coast FI number is simple: This equation kind of looks simple but it is not super intuitive always so maybe I explain a bit. You need to work out the Portfolio Balance Needed to Support Income Needs in Retirement. This means that you need to work out how much you need in a traditional retirement. How do you do that? Well that is why I say it might not be so complicated. Firstly, you need to know when you want to fully retire but you can work on a 65 year old target....