Speaking from experience, sanity depletes faster than one's retirement account increases with a draining job.
400k in SF is about 260k after taxes. Figuring saving 50% would give 130k/year in savings and an expense rate of 130k/year. At 8.0% returns, it would take 14 years to have enough to withdraw 4%/year match 130k.
Who says you need to match 130k? If you no longer have to work, you no longer need to live in the Bay Area. 70k would be luxurious in a less expensive place, if you take into account that you no longer have to work. Heck even 35k would be paradise. Many earn that while still working.
It's at the extreme end of the scale and will depend on your personality. Keep in mind that with 35K and no professional obligations you can do all of the following easily without any sacrifice in terms of leisure or family time or even energy levels:
- Shop around for healthy food at bargain prices
- Learn how to cook well and make the most of all that food
- Learn and have the time to fix 90% of maintenance issues
- Have the time and energy for sports and exercise
- Can dedicate more time to your family, kids need fewer toys because they have their father or mother back
- Travel for VERY cheap and you now have the time to actually do it at any time
- No longer a need to buy status or social class signaling goods because you no longer need to deal with professional expectations and setting a good impression in the minds of people you don't actually like
- Learn personal finance and your local legal system to maximize every drop
- No longer a need to buy things that make you cope with stress or long hours or even regular hours doing stuff you don't want to do
- As a corollary to the above, fewer risks of health issues, obesity, posture problems, alcoholism or self-medication, sleep disorders, psychological disorders, etc.
- Engage in creative pursuits
- Might no longer need a car in the traditional sense
To me that sounds like a better life than that of 99% of people who have ever lived. Now remember that we are talking about jobs and salaries for which a 4% rule at 70k or more is extremely doable. Which means you can not only have the life I just described but can also pay for your kid's education and the occasional health scare.
400k in SF is about 260k after taxes. Figuring saving 50% would give 130k/year in savings and an expense rate of 130k/year. At 8.0% returns, it would take 14 years to have enough to withdraw 4%/year match 130k.