Roth ConversionsYou can evaluate a conversion of a traditional IRA to a Roth by its effect on your after-tax asset allocation. If you are in the same tax bracket now that you expect to be in at retirement, and you pay taxes on the conversion with IRA money, the conversion is break-even. For example, if you are in a 25% tax bracket and convert a $40,000 IRA, you will have $30,000 in the Roth after paying taxes. Previously, you owned $30,000 of the IRA and the IRS owned the other $10,000; after conversion, you own the entire $30,000 in the Roth.
In contrast, if you pay the taxes with taxable money, you have a net gain, and it may even be worth making the conversion if you are going to be in a slightly lower tax bracket at retirement. If you are in a 28% tax bracket but expect to retire in a 25% tax bracket, and have $11,200 in a taxable account and $40,000 in an IRA, you own 75% of the IRA and probably about 75% of the taxable account, a total of $38,400. If you convert to a Roth, paying the taxes with the taxable $11,200, you will have a Roth worth $40,000.
The Advantage of a RothIf you can max out either a traditional or a Roth IRA or 401(k), you are likely to be better off with the Roth, because you effectively tax-defer more money. You can contribute the same number of dollars either way, but you own all of the Roth and not all of the traditional account.
Investing in the Roth in this situation is equivalent to investing in a traditional IRA and immediately converting it to a Roth, paying the tax with after-tax dollars. Therefore, if you are in a much higher tax bracket now than you will be in at retirement, the traditional account may still be better, but if the brackets will be equal or close, you should prefer the Roth.