<prompt> Human: My employer has recently started offering the Roth 401K plan, which I subscribed to, but I was looking to work out some of the details. I understand that Roth 401K contributions are post-tax i.e. taxed going in, however I noticed that on my most recent bi-weekly paystub, the amount is a percentage of my gross pay for the pay period. For example, if my total pre-tax pay for the pay period is 2500.00, and with 10 contribution it shows my Roth contribution as 250.00. Would this be correct? If so, would there be any difference with a traditional 401K?  <response>: You are putting in the 250, but you are still paying taxes on that 250, so your take home is lower than if you were contributing to a pretax 401k. 