If one contributes 15% of yearly income to a 401k and invests in the stock market (assuming 8% annual return factoring inflation), they will be able to retire in 28 years.
"set the 401k contribution slider to 15% of your yearly income and assuming that you're investing into the stock market which will give you 8% per year factoring inflation you'll be able to retire in 28 years regardless of your income"