The standard advice is simple: if you expect your tax rate to be higher in retirement, choose Roth. If lower, choose Traditional. But this framing misses critical factors — especially Required Minimum Distributions (RMDs), tax drag on the Traditional side account, and the fact that your Roth and Traditional retirement tax rates are actually different.
Most Roth vs. Traditional comparisons assume the same tax rate today and in retirement, then conclude it's a wash. But that's not how it works in practice. When you contribute to a Traditional IRA or 401(k), you get a tax deduction today. That tax savings should be invested separately — it's the "side account." If you don't invest the tax savings, you're not making an apples-to-apples comparison.
Here's what a proper comparison looks like: with a Roth, you contribute after-tax dollars that grow tax-free. With Traditional, you contribute pre-tax dollars, invest the tax savings in a separate taxable account (which faces annual capital gains tax drag), and then pay income tax on withdrawals in retirement.
The hidden factor: The Traditional side account is invested in a taxable brokerage account, where gains are taxed annually. This 15% long-term capital gains drag reduces the side account's growth, giving Roth a structural advantage even when tax rates are the same.
Starting at age 73, Traditional IRA owners must take Required Minimum Distributions — mandatory withdrawals based on account balance and life expectancy. These RMDs are taxed as ordinary income. Roth IRAs have no RMDs.
Here's why this matters for the comparison: your Traditional retirement tax rate should be based on your other retirement income plus your RMD, not just your other retirement income. If your Traditional balance grows to $1 million by age 73, your first RMD is approximately $37,700 (balance divided by 26.5). That $37,700 gets added to your Social Security and any other income, potentially pushing you into a higher bracket.
Your Roth retirement tax rate, on the other hand, is based only on your other retirement income — because Roth withdrawals are tax-free and don't count as income. This means Traditional and Roth have different effective retirement tax rates, even for the same person.
Consider a 30-year-old earning $80,000, single, contributing $7,500/year to an IRA in Florida (no state income tax), planning to retire at 65 with 7% annual returns.
Current marginal tax rate: 22% federal. The Traditional deduction saves $1,650/year in taxes, which gets invested in a side account.
By age 73, the Traditional IRA has grown to approximately $1.1 million. The RMD at 73 is about $41,500. Combined with Social Security of roughly $30,000, total retirement income on the Traditional path is $71,500 — putting the marginal rate at 22%. The Roth retirement rate based on Social Security alone is 12%.
After accounting for RMD-based taxes on the Traditional side and the tax drag on the side account, Roth comes out ahead by over $200,000 in after-tax retirement wealth. This surprises people because the current and retirement rates are both 22% on the Traditional side — but the tax drag and the RMD-driven rate difference tip the scales.
Traditional wins for high earners near retirement. If you're 55, earning $300,000, and will retire at 65, your current marginal rate is 35% and your retirement rate (even with RMDs) is likely lower. The ten years of growth isn't enough for the Roth structural advantages to overcome the large upfront tax difference.
Traditional also wins if you live in a high-tax state now and plan to retire in a no-tax state. Moving from California (13.3% state tax) to Florida in retirement creates a permanent tax rate reduction that favors the Traditional deduction today.
For 2026, IRA contribution limits are $7,500 per year ($8,600 if you're 50 or older). For 401(k) plans, the limit is $24,500 ($32,500 if 50+, and a special $35,750 limit for ages 60-63). Roth IRA contributions phase out at higher incomes — $153,000-$168,000 for single filers and $242,000-$252,000 for married filing jointly.
Enter your age, income, state, and retirement plans. The calculator uses 2026 tax brackets and models RMDs to show your after-tax retirement wealth in both accounts.
Run the analysis free →For most people under 50 with moderate incomes, Roth wins — often by a significant margin once you account for RMDs and tax drag. For high earners near retirement, Traditional usually wins. The commonly cited "same rate = same result" shortcut is wrong because it ignores the structural disadvantages of the Traditional path. Run the numbers with your actual situation before deciding.