Welcome!
On the topic of "how much will I need" -- obviously, if you change your lifestyle by travelling more, etc., there will perhaps be a financial impact.
However, to maintain your current lifestyle, here are some things that will reduce your expenses from today's spending:
- No more commuting; perhaps one less car, cheaper insurance, etc.
- No more work clothes, less dry cleaning, etc.
- No more work lunches
- Much reduced taxable income, so much reduced taxes]
- No more savings for retirement, through 401k, Social Security, and after-tax savings
You'll have to go through your own figures, but I'll bet you'll find that your current lifestyle costs you no more than half your gross pay.
Good luck!
Dory36