Invest in EFT's (low expense fees) or Mutual Funds (Actively Managed) 401K for Retirement

I am 26 and am wondering which route I should take.

I am debating on if I should invest $600 every month in ETF's (each with a $5 commission fee on TradeKing) with a expense ratio of about .13% or the same amount of money in my 401k mutual fund with a expense ratio of .56%? They are both Roth retirement accounts. Is there a formula I could use to calculate which would be more profitable in the long run?

Submitted February 18, 2016 at 11:22AM by jhenn08 http://ift.tt/20GJotv