Roth and Traditional IRAs share the same 2026 contribution limit: $7,500, or $8,600 if age 50 or older. The difference is when you pay tax: now for Roth contributions or later for deductible Traditional IRA contributions and earnings.

Here’s how to pick correctly.

The one-sentence rule

Pick the account that’s taxed at the LOWER rate. If your current tax bracket is lower than the bracket you expect to be in at retirement, choose Roth. If it’s higher, choose Traditional. If they’re equal, the two are mathematically identical.

That’s the entire decision. Everything below is how to make that comparison accurately.

How each account works

Traditional IRA:

  • Contribution is tax-deductible now (subject to income limits if you have a workplace plan).
  • Investments grow tax-deferred.
  • Withdrawals in retirement taxed as ordinary income.
  • Required Minimum Distributions (RMDs) start at age 73.

Roth IRA:

  • Contribution is made with after-tax money, no deduction.
  • Investments grow tax-free.
  • Qualified withdrawals (age 59½, account 5+ years old) are completely tax-free.
  • No RMDs during the original owner’s lifetime.

Same $7,500 base limit. Same broad investment menu. Different tax timing.

The math: an apples-to-apples comparison

The comparison must account for the Traditional IRA’s current deduction. At a combined 26% marginal rate, a deductible $7,500 Traditional IRA contribution saves up to $1,950 of current tax; a Roth contribution does not.

TraditionalRoth
2026 contribution$7,500$7,500
Value after 30 years at 7%About $57,100 before withdrawal taxAbout $57,100 after qualified withdrawal
Current-year deductionUp to $1,950 at a 26% marginal rate, if deductible$0
Retirement taxOrdinary income tax applies$0 on qualified withdrawals

For an equal-effort comparison, invest the Traditional IRA tax saving rather than spend it. The result then depends primarily on the difference between today’s marginal tax rate and the effective rate on future withdrawals, plus any tax drag on the side account.

Our Roth IRA Calculator and Traditional IRA Calculator both do this comparison honestly. You can compute a clean side-by-side using the same inputs.

When Roth wins

  • You’re in the 12% bracket or lower today. Your retirement bracket is almost certainly higher.
  • You’re early-career and expect significant income growth.
  • You think tax rates will rise (US debt + entitlement reform is a real driver).
  • You value the estate-planning advantage: Roth IRAs pass to heirs tax-free; Traditional IRAs trigger the 10-year drain rule under the SECURE Act.
  • You want flexibility: Roth contributions (not earnings) can be withdrawn at any time, penalty-free.

When Traditional wins

  • You’re in the 32% bracket or higher today and expect lower spending in retirement.
  • You’re close to retirement (5-10 years) and your current bracket will fall once W-2 income stops.
  • You’re saving for a defined retirement target rather than legacy/heirs.
  • You expect to relocate to a no-income-tax state in retirement (turns a state tax deduction now into a 0% withdrawal then).

When the answer is “split”

If you do not know your future bracket, splitting the $7,500 base limit, for example $3,750 Roth and $3,750 Traditional, can create tax diversification. The combined contribution across both IRA types cannot exceed the annual limit.

Income limits matter (Roth especially)

For 2026, Roth IRA contributions phase out at:

  • Single / Head of Household: $153,000–$168,000 MAGI
  • Married Filing Jointly: $242,000–$252,000 MAGI

Above those caps, direct Roth contributions are barred. The workaround is the Backdoor Roth IRA, contribute non-deductible to a Traditional IRA, then convert. Legal and common, but the pro-rata rule complicates it if you have other pre-tax IRA balances. See our Backdoor Roth Calculator for the full math.

Traditional IRA deduction limits are tighter if you (or your spouse) have a workplace retirement plan:

  • Single/HOH active participant: Deduction phases out $81,000–$91,000
  • MFJ, contributing spouse is an active participant: $129,000–$149,000
  • MFJ, contributor is not covered but spouse is: $242,000–$252,000

Above these, you can still contribute to a Traditional IRA, you just don’t get the deduction. That converts the math into a non-deductible Traditional, which is almost always worse than a Roth or a Mega Backdoor Roth (if your 401(k) allows it).

Common mistakes

Contributing to both at once when one is barred. If your income is above the Roth limit, contributing direct-Roth triggers a 6% annual excise tax on the excess. Use the IRA contribution form correctly or convert via Backdoor Roth.

Thinking the 5-year rule doesn’t matter. It does. Each Roth conversion starts its own 5-year clock for penalty-free early withdrawal of the converted amount. Younger savers planning to retire pre-59½ need to factor this in.

Confusing “Roth” with “tax-free forever.” Roth IRA earnings are tax-free at qualified withdrawal. Early withdrawals of earnings (not contributions) trigger income tax + 10% penalty.

Forgetting the spousal IRA. A married couple filing jointly may use combined taxable compensation to fund an IRA for each spouse, up to $7,500 each before catch-up in 2026.

A simple decision flowchart

  1. Is your current marginal rate ≤ 12%? → Roth.
  2. Is your current marginal rate ≥ 32%? → Traditional (deductible if eligible).
  3. Are you in 22% or 24%? → Split, or default to Roth if you expect rising bracket.
  4. Are you above Roth income limits? → Backdoor Roth (if no pre-tax IRA balance), or Traditional non-deductible.

For specific numbers, run both options through the Roth IRA Calculator and Traditional IRA Calculator using identical assumptions and compare net retirement spending power.

Other countries

The Roth-vs-Traditional choice is uniquely American. Other countries have analogous account types:

  • United Kingdom, ISA (tax-free, no deduction, like Roth) vs SIPP (deductible, like Traditional)
  • Canada, TFSA (Roth-like) vs RRSP (Traditional-like). The TFSA vs RRSP framework is even closer to the Roth/Traditional debate.
  • Australia, Concessional vs non-concessional Super contributions
  • India, EPF + NPS (mostly deductible) vs equity LTCG ₹1L exemption

We’ll cover each in country-specific guides.

Primary sources