In order to safely plan for a successful retirement, it’s imperative to have a general idea of what your spending needs will be when retired.
We cannot calculate whether or not our anticipated withdrawal rate would be considered safe (in the range of 3% to 4%) without knowing the size of the annual withdrawal.
Fortunately, there are a number of categories in which your annual expenses can be expected to drop when you give up the day (and sometimes night) job.
Commuting costs many of us not only time, but money, and perhaps more money than we realize. I tend to think of the cost of driving in terms of the price of gasoline, but that ignores so many periodic expenses.
Once your retirement is fully funded, and you stop working for a living, you no longer have that perceived outflow.
Taking advantage of geographic arbitrage while working in a high-income specialty but living in a high-tax state, we found ourselves in the mostly fortunate position to pay six-figure tax bills throughout much of my career.