<prompt> Human: My company provides both 401k and Roth 401k. There is no company match unfortunately for either. I am contributing 18.5k to my 401k right now. Recently i have been thinking if I should move some of itall of it to Roth 401k.Some friends have been telling me its better to invest in post tax retirement as tax rate is likely going to be much higher when I retire 25 years looking at how the political climate of the country and economy is going. But I am already at a pretty high tax rate right now, Im 28, I make about 120k, I am single, no house, no student debt. So I barely have any deductions I can claim. Is there any sense for me to move my contributions to Roth 401k?Any benefits of doing this?  <response>: If you dont want to think hard, then going 100 Roth is reasonable.However, a mix of pre-tax 401k and Roth 401k is goodness.When you retire you will have 5 sources of income: Social Security pre-tax 401k andor rollover pre-tax IRA Roth 401k andor rollover Roth IRA Backdoor Roth Taxable investmentsThis boils down to: Taxable: social security, pre-tax 401kIRA, taxable accounts Tax free: Roth 401kIRAThe goal is to keep yourself in the lowest tax brackets in retirement. Lets say the tax brackets when you retire are the same as today: 100 129,525 2238,700Big jump from 12 to 22. For sake of argument, lets say you draw the line at 22: i.e. you refuse to pay it.So you want to keep your taxable income below 38,700. Keep in mind that you have 12K standard deduction, so the gross is about 51K before you pay 22 on the excess income.Unfortunately Social Security is subject to taxes now, but I think up up to 85. The other factor though is that the longer you wait to start collecting, the higher the payments.You have said your goal is to retire at 53. You can actually start collecting 401k penalty free if you stop working the year you turn 55. And there are other ways to collect 401kIRA penalty free before 59.5, even before 55. Just assume it can be done.With pre-tax 401IRA, you can defer collecting social security and still pay very low taxes.So you would front load your pre-social security years with pre-tax 401kIRA distributions, paying an average tax below 12 overall.Then you start collecting social security. It is anyones guess what your payment will be because of the demographic shifts. Lets say it is 25K a year. That leaves about 25K you can draw from pre-tax 401kIRA. But lets say you do really well in next 25 years, and taking 25K a year from your retirement funds is far less than the 3-4 safe distribution rate. So you want to live larger than 51K year lifestyle, but you dont want to pay lots of taxes. So you might mix it up: 25K social security 25K pre-tax 401kIRA 25K Roth 401kIRAEventually you might deplete all your 401kIRA and then you live on taxable investments. You should have been investing in either a broad index like the SP 500. Regardless, you will be paying at most capital gains tax, and if you harvest redemptions correctly, you will balance shares that have a capital loss against shares with a capital gain to minimize tax.The other factor to consider is that you do not own a home. If that continues into retirement, having Roth 401kIRA to shield you from rent hikes without paying more taxes will be a god send. 