Same dollars, different tax timing. The right choice depends on one thing: your tax rate now versus later.
How they differ
Traditional IRA: contributions may be deductible now; you pay tax on withdrawals in retirement. Roth IRA: no deduction now; qualified withdrawals are completely tax-free. Both grow tax-deferred inside the account.
The tax-rate rule
With equal pre-tax dollars, the lower tax rate wins. In a high bracket now and expecting less in retirement? Traditional. Early career with rising earnings ahead? Roth — you are locking in a low rate. Compare your exact numbers in the Roth vs Traditional IRA Calculator.
A worked example
Invest 7,000 pre-tax yearly for 30 years at 7% — it grows about 7.6x. Traditional, taxed 15% at withdrawal: roughly 45,293 after tax. Roth, taxed 22% upfront: roughly 41,563 tax-free. Traditional wins by about 3,730 here, purely because the retirement rate is lower.
Beyond the maths
Roth advantages: no required minimum distributions, tax-free money for heirs, and you can withdraw contributions (not earnings) anytime without penalty. Traditional advantages: the deduction today, which is real money if you are in a high bracket. Employer plans often offer Roth 401(k) too, with much higher limits.
The hedge: do both
Nobody knows future tax rates. Splitting contributions between Roth and Traditional is tax diversification — whatever rates do, part of your money is positioned well. For most people, that beats agonising over the perfect choice.
Watch the limits
For 2026, the combined IRA limit is 7,000 (8,000 if 50+). Income phase-outs restrict Roth eligibility and Traditional deductibility — check the current IRS thresholds before you contribute.