I agree with vasco that 12% is a very large expectation for compound interest. In the early-retirement community 7% (before inflation) is a good benchmark over

I agree with vasco that 12% is a very large expectation for compound interest. In the early-retirement community 7% (before inflation) is a good benchmark over long periods of time. However, your tax assumptions are probably too high for the current environment. If you earn 100k gross, but max out your 401k and HSA, your net income after taxes will be close to 60k, but you'll already be saving 20k+ pre-tax. Yes, you'll have to pay taxes on the 401k when you reach retirement, but if you're living frugally and only taking out a small amount, your tax obligations will be way less than 35%. Without breaking a sweat, my effective tax rate is under 16% and I'm in the range described.