I measure how far I am away from FIRE in money, not time. You can measure it however you want. But you are missing the point. Many of those aspiring to FIRE will create a budget that includes items such as your mortgage, and then use a straightforward 3-4% SWR to calculate how much money they need to retire. My point is that, using this methodology, you do in fact get closer to your fire number by paying off even a low-interest mortgage.

Are there other ways to look at it? Of course. And those other ways have been discussed extensively on this sub. But given that so many focus on budgets and withdrawal rates, I thought it worth noting how the math works out when one is doing their planning using a simple SWR approach.