how much to contribute to roth 401k
By Investopedia AAA |. A: The maximum amount that a person can contribute to his Roth 401(k) for the calendar year 2015 is $18,000, or $24,000 for those over age 50. These are the same maximum contribution amounts permitted for a traditional 401(k).his means an investor under age 50 can invest $10,000 in a Roth 401(k) and $8,000 in a traditional 401(k) and vice versa.