I certainly do. I use Quicken to keep track of my accounts and investments, and incidently track my expenses. Given that I have complete financial records of everything I've spent over the last 10 years or so, budgeting the non-discretionary expenses is easy. I don't really like the budgeting feature of Quicken, but it does make it simple since you just tell it to fill in the average monthly spending in each essential category.

Of course, discretionary expenses are what budgeting is really all about. Aside from some luxuries (like cable TV), I lump everything under "Recreation Gus" or "Recreation Debbie." Each of these categories has several sub items, like "Books", "Games", etc., but the total for each lump is fixed at no more than $500 a month for each of us.

For scale, I am currently sending $3K-$4K a month to our American Express brokerage account to invest against FIRE. This is approximately 50% of our take home pay.

- Gus