Roth vs Traditional IRA: which one wins?
It comes down to one question: is your tax rate in retirement higher or lower than today's? Most people guess wrong about which.
The one question that matters
Will your tax rate in retirement be higher or lower than your current marginal rate?
- If higher in retirement → Roth wins. Pay tax now at the lower rate.
- If lower in retirement → Traditional wins. Take the deduction now at the higher rate.
- If identical → mathematically equivalent.
Plug today's contribution and your expected retirement-year tax rate into the Roth IRA and Traditional IRA calculators side-by-side to see the dollars.
Why people guess wrong
The intuition "I'll be in a lower bracket in retirement" sounds right because retirees usually earn less. But three forces push the other way:
- Tax brackets are not indexed to your career arc. If today's 22% bracket pays for the federal budget, future deficits make it likely brackets drift up over decades, not down.
- Required Minimum Distributions (RMDs) from a traditional IRA at age 73 force taxable income whether you need the cash or not — bumping retirees into higher brackets they'd have skipped.
- State tax in retirement. If you're in a no-state-tax state today and may move to one with state tax (or vice versa), that flips the comparison.
When Traditional clearly wins
- You're currently in the 32% federal bracket or higher.
- You expect to retire early and live on a much lower income for several years before Social Security kicks in (giving you a window for cheap Roth conversions).
- You live in a high-state-tax state today and plan to move somewhere with no state tax in retirement.
When Roth clearly wins
- You're young, in the 12–22% bracket, and expect peak earnings later.
- You want to leave the account to heirs — Roth has no RMDs and is much more tax-efficient on inheritance.
- You expect your post-tax income (Social Security + a brokerage account + withdrawals) to push you into a higher bracket than today's.
The under-discussed third path: do both
Tax-rate forecasts decades out are speculative. A 50/50 split between Roth and Traditional gives you the flexibility to pull from whichever is more tax-efficient in any given retirement year — bracket-fill from Traditional up to the next breakpoint, top up from Roth.
Tools to use next
- Roth IRA — tax-free retirement projection.
- Traditional IRA — pre-tax deferred projection.
- 401(k) — model employer matches alongside.
- Retirement — full deterministic + Monte Carlo nest-egg projection.
- RMD — what your traditional IRA will force you to withdraw.