Make the comparison use the same dollars
A popular chart deposits $7,500 in both a Traditional and a Roth IRA, applies one growth rate, then calls Roth the winner because its qualified withdrawal can be tax-free. That skips the tax paid before the Roth deposit. To compare fairly, start with the same amount of pretax income available to save and decide where the income tax is paid. A Traditional contribution may be deductible if the person qualifies; a Roth contribution is not deductible. The IRS's IRA comparison states that distinction, but neither account guarantees a particular return.
Suppose Maya has $7,500 of pretax income earmarked for retirement, a 24% current marginal federal rate, enough compensation, and full Traditional deductibility. She can deposit $7,500 in a Traditional IRA and defer the tax, or pay $1,800 of current tax and deposit $5,700 in a Roth IRA. In practice the Traditional deduction may come through withholding or a later return rather than arriving immediately in her bank account. The example compares economic cost, not the exact timing of a refund. State tax, investment fees and future law changes are excluded.
Run the rate crossover yourself
Assume both deposits earn 6% annually for 20 years with no further contributions. That is an illustration, not a market forecast. The compound factor is 1.06^20, about 3.2071. Traditional grows to about $24,053.52 before withdrawal tax; Roth grows to about $18,280.67. If Maya's effective tax on the Traditional withdrawal is 12%, she keeps about $21,167.09. At 24%, she keeps $18,280.67 and the two routes tie. At 32%, she keeps about $16,356.39 and Roth comes out ahead in this simplified case.
Value after 20 years from the same $7,500 pretax budget
This crossover is a property of the assumptions, not a recommendation to choose one account. A withdrawal may span several tax brackets, while a contribution saves tax at the margin. Taking $24,000 from an IRA in retirement need not mean every dollar is taxed at the retiree's highest bracket. Social Security taxation, health coverage and state tax can also alter the comparison. Do not plug one headline tax rate into every future dollar without explaining why.
Check whether the 2026 contribution is allowed
The IRS's 2026 adjustment notice sets the annual IRA contribution cap at $7,500, plus a $1,100 age-50 catch-up, for $8,600 total when eligible. That is a combined limit across your Traditional and Roth IRAs, not $7,500 in each. Your taxable compensation can also limit contributions. A contribution to a Traditional IRA is possible without a deduction, but you must track nondeductible basis, generally using Form 8606.
Combined 2026 Traditional-plus-Roth IRA contribution limit
If Maya is single and covered by a workplace retirement plan, her Traditional IRA deduction phases out over modified adjusted gross income of $81,000–$91,000 in 2026. That is not the same test as the Roth contribution phase-out for a single filer, $153,000–$168,000. For a married joint filer with the contributor covered at work, the Traditional deduction phase-out is $129,000–$149,000; Roth eligibility phases out over $242,000–$252,000. The spouse-covered-but-contributor-not-covered situation has its own range. All these numbers are from the same IRS 2026 notice.
The result is a two-step decision: first check eligibility and deductibility; only then compare tax timing. A person above the Traditional deduction ceiling cannot assume Maya's $1,800 current deduction. A person above the direct Roth income ceiling cannot use the direct Roth example without separate analysis of other lawful routes and their tax consequences.
Qualified withdrawal is a condition, not a label
A Roth contribution is made with after-tax money. Its earnings are tax-free only when distribution requirements are met. The IRS IRA topic describes the five-tax-year period and age-59½ or another qualifying condition. Taking money early can change the result; the ordering rules distinguish contributions from earnings. A Traditional IRA's deductible contributions and growth are generally taxable when withdrawn, and early taxable distributions can face an additional tax unless an exception applies.
Traditional IRAs generally have required minimum distributions at the applicable age, while an original Roth IRA owner generally does not. The applicable RMD start age depends on birth cohort and law, so check the IRS RMD guidance rather than assuming one age fits all. A Traditional-to-Roth conversion is also a different taxable event; it is not the same as choosing where to put a new 2026 contribution. Publication 590-B covers distribution rules and exceptions.
Use the model as a decision worksheet
Write down four facts before choosing: the amount of earned compensation, your filing status and workplace-plan coverage, the current tax saved by an actual deductible contribution, and the tax treatment you expect when withdrawing. Then run at least a lower, equal and higher future-tax case, not only the one that confirms your preference. If you cannot deduct a Traditional contribution, the model above is the wrong comparison. If you may need the money before retirement, model the withdrawal rules rather than treating either IRA as a generic savings account.
If Maya expects to retire gradually, do not substitute her highest anticipated bracket for the rate on every Traditional dollar. A partial withdrawal may fill unused lower brackets before a higher rate applies; other taxable income and filing status determine how much room exists. Conversely, a Roth balance can be useful in a year with unusually high taxable income, but that flexibility matters only after its distribution is qualified. Neither point justifies assuming future tax law will match today’s schedule.
A mix of Traditional and Roth savings can diversify future tax choices, but there is no universal percentage for that mix. Check your own MAGI and IRS contribution limit, then revisit the choice when your income, tax law or retirement horizon changes. The dollar results here demonstrate the tax-budget method; they are not personalized tax advice.
