What I did a long time ago was create a spreadsheet for this. It started out simple and got more complex over time.
Each row in my spreadsheet represented a month. Each column in my spreadsheet represented an account.
So you could do something like:
401k Vanguard Total
Oct-17 555,000 500,000 =sum(401k,Vanguard)
Nov-17 ?
Dec-17
So for November-17 for the 401k, I would put a formula that was something like =(PrevBalance+AnnualContrib)*(AnnualRateOfReturn/12). Same thing for Vanguard for November-17.
Once you've done that for each account and got the row for November-17 done, you can copy-paste the rows down as far as you want until you see a Total that represents 25x your annual spending or whatever target you've set for yourself. Right now if your expenses are about $40K you're probably close to retiring. But you're a high income type so that probably seems too low. In another 5 years you'll probably be able to withdraw $80K-$90K. Remember that when you retire you only have to pay for your spending, not your savings. Also, if you're that high income now, your taxes will likely drop considerably when you stop working, because - roughly speaking - you'll be taxed on the $60K you're spending that year, not the $250K you're no longer earning.
Good luck!