I was just looking at our investments in Mint. Our tax sheltered retirement accounts are just under $350k. I'm 41 and my husband is 43. If we never put another dime in there but reinvest dividends/earnings, by the time I reach 66, assuming an 8% return, I get that gives us a balance of $2.4 million and a SWR of $95k per year. Is my math right?

Well the math is right if you're assuming a 4% SWR (you'll have about 96k/yr).

Here's the caveat: 2.4MM in 25 years won't be worth nearly what it is now (ditto the 95k income), and an 8% real return (i.e. after inflation) seems unlikely.

Better, IMO, to think of it in real dollars. So if you assume an 8% return and 3% inflation (so 5% real return), then you'd have 2.4MM in nominal dollars at that time, but that'd be equivalent to ~1,185k in today's dollars, or (at a 4% SWR) about $47,000 per year in today's dollars.

But yes, all your math was correct, just adding that on as well. :)