Well here’s a fun one. I have two primary ways of looking at this question:
(1) I want to calculate how my current lifestyle impacts my FIRE timeline; or
(2) I want to calculate savings rate to see how much of my gross/net income goes to something classified as “savings,” period.
I assume our mortgage principle is “savings”, and the only difference between #1 and #2 above for me is that my student loan payment would otherwise be savings - so clearly, I don’t have to make a lifestyle change going forward to compensate for them, I just have to pay them off.
Under #1, with my student loan payments counted as “savings” since they otherwise would be saved at our current lifestyle, me and Mrs. Vigilante have a savings rate this year of just shy of 70% of gross and a whopping 136%-ish of net income! Lifestyle’s pretty good, I figure
Under #2, with my student loan payments counted solely as an expense since it all leaves my pocket, we have a savings rate of about 50% of gross and still 105% of net income. I love seeing that we’re saving more than we bring home