Roth vs TraditionalIRA Calculator

Roth vs Traditional IRA: The Tax-Now vs Tax-Later Decision Framework

The IRA (Individual Retirement Account) was codified under IRC §408, with the Roth variant added via IRC §408A through the Taxpayer Relief Act of 1997. The fundamental distinction between the two account types is simple: a Traditional IRA allows a pre-tax contribution (reducing your taxable income today) with distributions taxed as ordinary income in retirement, while a Roth IRA accepts after-tax dollars that then grow and are distributed completely tax-free. For 2026, the IRS sets the annual contribution limit at $7,000 for individuals under 50 and $8,000 for those 50 and older under the catch-up contribution provision, which are limits that apply across all of your combined IRA accounts, not per account.

The question of which account type wins is fundamentally a tax rate arbitrage problem. If your current marginal federal tax bracket is lower than your expected bracket in retirement, a Roth IRA wins: you pay a small tax rate today to lock in decades of compounding growth that is never taxed again. Conversely, if you are in your peak earning years (say, the 32% or 35% bracket) and expect a lower effective rate in retirement drawing from Social Security and portfolio distributions, the Traditional IRA's immediate deduction is more valuable. The break-even point is when your current and future marginal rates are identical: in that case, both accounts produce mathematically equivalent after-tax outcomes, assuming the Traditional IRA tax savings are reinvested.

Roth Income Phase-Out Ranges and the Backdoor Roth Strategy

Direct Roth IRA contributions are subject to Modified Adjusted Gross Income (MAGI) limits. For 2026, the phase-out range for single filers begins at $150,000 and ends at $165,000; for married filing jointly, the range runs from $236,000 to $246,000. Above these ceilings, direct Roth contributions are completely prohibited. High earners are not locked out of the Roth's tax-free growth benefit, however. The Backdoor Roth IRA is a two-step, IRS-sanctioned strategy: make a non-deductible contribution to a Traditional IRA (which carries no income ceiling), then immediately convert it to a Roth IRA. The conversion is taxable only on any earnings accrued between the contribution and conversion dates, which are typically near zero if done promptly. High earners with existing pre-tax IRA balances must account for the pro-rata rule, which blends pre-tax and after-tax IRA money and may create an unexpected tax bill on conversion.

Traditional IRA deductibility has its own phase-out rules that interact with workplace plan participation. If you or your spouse are active participants in an employer-sponsored 401(k) or 403(b), your ability to deduct Traditional IRA contributions phases out at lower MAGI thresholds, starting at $79,000 for single filers and $126,000 for MFJ in 2026. Above those limits, Traditional IRA contributions become non-deductible, stripping away the key tax benefit while still locking in the account's less flexible distribution rules. In most such cases, a Roth IRA (or the backdoor strategy if over the income ceiling) is the superior choice. For a complete breakdown of when each account wins, read our detailed guide: Traditional vs Roth IRA: Contribution Rules, Phase-Outs & Tax Strategy.

Required Minimum Distributions and the Long-Term Case for Roth

One structural advantage of the Roth IRA that pure tax-bracket math often understates is the absence of Required Minimum Distributions (RMDs). Traditional IRAs require annual withdrawals beginning at age 73 under SECURE 2.0 Act rules, forcing taxable income regardless of whether you need the money. These RMDs can push retirees into higher brackets, trigger Medicare IRMAA surcharges, and make more Social Security benefits taxable, which creates a cascade of unintended tax consequences. Roth IRAs carry no RMD requirement during the account owner's lifetime, making them exceptionally powerful for estate planning and tax-managed retirement income. The flexibility to leave Roth assets untouched for decades of continued tax-free compounding is a benefit that extends well beyond the simple contribution-year tax rate comparison most calculators model.