Originally Posted by wab
I don't consider paying myself to be an expense, but a better question might be how to handle your mortgage payment for planning purposes with FIREcalc.
FIREcalc doesn't have an amortization calculator. It also doesn't understand that the principal payment comes back to you, or that the interest payment doesn't go up with inflation.
So, you probably want to exclude your entire mortgage payment from the "expense" entry in FIREcalc, and use the non-inflation-adjusted "increase withdrawals" field for your average interest payment over the remaining life of your mortgage.
I'm realizing based on the feedback that the biggest factor I need to consider is whether or not I plan on eventually downsizing my house in order to recapture the 'savings' that I'm convincing myself of making. If I plan on living in my current house forever, then I would agree with the 'principal=expense' crowd and say that it is indeed an expense, but I am planning (although 20 or so years down the road) of moving to a lower cost locale and getting that principal back, so I guess I'll keep thinking of it as a non-expense.
However, I like wab's 'switzerland' response the best - it seems like the best way to model the situation within FIRECALC w/o caring about whether it is or isn't an expense, and I hadn't considered this previously. (I'm going to try it out right now)