So, a percent of salary that is going towards a 401k (hopefully with a company match) is one factor, but it's not the end of the world if it's low. For me, I'm at 6% (to get the full company match of 3%). And almost every year they give an extra bonus of company stock (they call it equity builder), of like 2% or so in the spring. And of course, someone making 40k/year putting 12% away vs someone making 80k/year putting 7% away.. the second person is putting more actual money away.