The average 401(k) participant contributes 6.2% of income. According to the Vanguard “How America Saves” report, the average deferral rate was 6.2% in 2016, not including employer matching contributions. This is down significantly from 6.9% in 2015, and a big reason for the decline is the rise in automatic enrollment programs, which often have default contribution rates of 3% or less. Experts generally suggest that workers should aim to defer 10% of their salary for retirement.