Roth vs Traditional comes down to one question: will your tax rate be higher or lower in retirement than it is today? Roth contributions are taxed now and then grow and withdraw tax-free. Traditional contributions are deducted from this year’s taxable income and then taxed when you withdraw. If your retirement tax rate will be lower than today’s, Traditional usually wins. If it’ll be higher, Roth wins. And if the rates are equal, the after-tax result is exactly the same — that’s the break-even point.
Run your own numbers with the Roth vs Traditional Break-Even Calculator. Here’s why the math works the way it does.
The break-even, in plain math
Imagine you commit the same pre-tax dollars and earn the same return. The only difference is when the tax is applied:
- Roth: pay tax up front, then multiply by growth. After-tax value = contribution × (1 − tax now) × (1 + r)ⁿ.
- Traditional: invest the full amount, then pay tax at the end. After-tax value = contribution × (1 + r)ⁿ × (1 − tax later).
Notice the two formulas are identical except for which tax rate you multiply by. Multiplication is commutative, so if tax now = tax later, the results match to the penny. The growth term cancels out of the decision entirely. The choice depends only on the two tax rates — not on your return or your time horizon.
When each one wins
| Your situation | Likely winner | Why |
|---|---|---|
| Early career, low bracket now, expect higher income later | Roth | Lock in today’s low rate; withdraw tax-free at a higher future rate. |
| Peak earnings now, expect lower spending/bracket in retirement | Traditional | Take the deduction at today’s high rate; pay tax later at a lower one. |
| Unsure about future rates | Split both | Hedge against tax-law and income uncertainty. |
| Want tax-free money for heirs / no RMDs | Roth | Roth IRAs have no required minimum distributions for the original owner. |
| Need the deduction to free up cash to invest | Traditional | The up-front tax saving can be reinvested. |
The 2026 limits you’re working with
Contribution limits rose for 2026. These come straight from IRS Notice 2025-67:
| 2026 limit | Amount |
|---|---|
| IRA contribution (Roth or Traditional, combined) | $7,500 |
| IRA catch-up (age 50+) | $1,100 (total $8,600) |
| 401(k) elective deferral | $24,500 |
| 401(k) catch-up (age 50+) | $8,000 (total $32,500) |
| 401(k) catch-up (ages 60–63) | $11,250 |
| Roth IRA phase-out — single | $153,000–$168,000 |
| Roth IRA phase-out — married filing jointly | $242,000–$252,000 |
Two practical notes. First, the IRA limit is a combined cap — $7,500 total across all your IRAs, not per account. Second, Roth IRA eligibility phases out at higher incomes. Above the top of the range, you can’t contribute to a Roth IRA directly (though a Roth 401(k) has no income limit, and the “backdoor Roth” exists — talk to a professional). Traditional IRA deductibility also phases out if you’re covered by a workplace plan.
Why “tax now vs tax later” is harder than it sounds
The theory is clean, but predicting your future tax rate is genuinely difficult:
- Tax brackets change. Today’s rates aren’t guaranteed to last. Many savers favor Roth partly to hedge against future rate increases.
- Required minimum distributions (RMDs) force taxable withdrawals from Traditional accounts later in life, which can push you into a higher bracket than expected.
- Roth has no RMDs for the original owner, giving you more control over your taxable income in retirement.
- State taxes can differ between your working years and retirement if you move.
Because of this uncertainty, “split the difference” is a popular real-world answer. Holding both Roth and Traditional gives you tax diversification — knobs to turn in retirement to manage your bracket year by year.
A worked example
You contribute $7,500 for 30 years at a 7% return, with a 24% tax rate today and an expected 22% rate in retirement.
- Roth: $7,500 × (1 − 0.24) grows to roughly $43,400 after-tax (tax-free out).
- Traditional: $7,500 grows to about $57,100, then × (1 − 0.22) ≈ $44,500 after-tax.
- Traditional edges ahead by about $1,100 here — because the retirement rate (22%) is lower than today’s (24%).
Flip the retirement rate to 27% and Roth pulls ahead. The break-even calculator finds the exact crossover for your inputs.
Order of operations for 2026
Whichever account type you choose, the priority order rarely changes:
- Capture your full employer 401(k) match first — it’s free money no tax strategy can beat. See 401(k) Match: Don’t Leave Free Money.
- Fund an IRA (Roth or Traditional) up to $7,500, choosing based on the tax logic above.
- Return to the 401(k) up to the $24,500 elective limit.
- Let compound growth do the rest as you march toward your FIRE number.
This is general information and an estimate, not financial or tax advice. Tax situations are personal and the rules are intricate — confirm the limits with the IRS and consult a qualified tax professional before deciding. But once you understand that the whole debate reduces to two tax rates, the choice gets a lot less intimidating.