Roth vs Traditional Comparator
Compare Roth (pay tax now, withdraw tax-free) vs Traditional (deduct now, taxed later) retirement contributions. See after-tax final value, the winner, the crossover tax rate, and a multi-scenario table.
Roth vs Traditional Comparator
Your contribution
Tax rates — the key decision driver
- After-tax contribution / yr
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- Final balance
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- Tax on withdrawal
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- Net spendable
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- Pre-tax contribution / yr
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- Final pre-tax balance
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- Tax on withdrawal
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- Net spendable
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Scenario table — Roth vs Traditional at different retirement tax rates
How to use the Roth vs Traditional Comparator
Enter your annual contribution and time horizon
Use whatever you actually plan to contribute each year (for 2025 the IRA limit is $7,000, or $8,000 if age 50+). 401(k) limit is $23,500 (+$7,500 catch-up). For Singapore SRS the cap is S$15,300 for citizens/PRs (S$35,700 for foreigners). Years until retirement = how long the money will grow before you withdraw.
Enter both tax rates — current and expected retirement
Current = your marginal rate on the next dollar earned (federal + state combined in the US, or your country's top bracket you currently sit in). Retirement = your honest forecast — most retirees end up lower (less income → lower bracket), but high earners with large pensions, RMDs, and rental income often stay flat or higher.
Set an expected real return
Real means inflation-adjusted. Long-term US equity real return is ~6.5-7%. Mixed 60/40 portfolio ~4-5%. Bonds ~1-2%. Be conservative — the comparison still works on relative basis but inflated returns make the dollar advantage look bigger than reality.
Read the winner + crossover analysis
Key insight: the winner depends entirely on the gap between your current rate and your retirement rate. Roth wins when retirement rate > current; Traditional wins when retirement rate < current. The crossover point is exactly equal to your current rate — at that point both paths tie algebraically. The scenario table shows what happens across the plausible range.
Roth vs Traditional — the entire decision hinges on one comparison
Pick almost any retirement-savings article and you'll find pages of arguments about Roth vs Traditional. The actual math is a one-liner: if your tax rate when you withdraw is HIGHER than your tax rate when you contribute, Roth wins. If LOWER, Traditional wins. If EQUAL, they are mathematically identical. That's it. Everything else — flexibility, RMDs, estate planning, backdoor strategies, mega-backdoor strategies — is a layer on top of this base case. The algebra is symmetric because growth is tax-free in both vehicles; the only difference is when the tax is applied. Multiplication commutes: (1 − tax) × (1 + r)N equals (1 + r)N × (1 − tax) when the tax rate is the same in both factors. That's why, at equal tax rates, the two paths produce the exact same after-tax dollar.
Why younger workers usually default to Roth, older workers to Traditional
A 25-year-old software engineer earning $70,000 sits in the 22% federal bracket. By age 60 she may earn $250,000 and sit in the 32-35% bracket. Contributing Roth at 22% and withdrawing tax-free at retirement — when her income stops and she drops back to the 12-22% range, OR continues at the 32%+ bracket — is a clear win in either case. Conversely, a 55-year-old executive in the 35% federal bracket plus state, expecting to retire to a low-cost state and live on $80K from a mix of Social Security and portfolio drawdowns (effective rate ~12-15%), should fill the Traditional bucket aggressively. The cap on Traditional benefits is your peak earning years — those are exactly when the deduction is most valuable. Roth is a younger-person and high-saver play; Traditional is a high-earner and peak-bracket play.
Roth vs Traditional is not a religious war. It is a one-line algebra problem about whether your future tax rate is higher or lower than your current one — and an honest admission that nobody truly knows the answer.
Why tax diversification beats picking just one
Here's the uncomfortable truth: no one knows their future tax rate. US federal rates are at historic lows (top bracket 37% vs 70%+ pre-Reagan, 91% in the 1950s). The fiscal trajectory — entitlement demand, deficit, demographic shift — suggests rates will rise, not fall. But tax policy is unpredictable: SECURE 2.0 added Roth catch-up requirements, expanded Roth 401(k) employer matching, and quietly extended RMD ages. Future Congress may means-test Social Security based on Roth balances (introducing a hidden tax on Roth). Future Congress may impose a wealth tax or a consumption tax. The honest answer is to hedge: split contributions between Roth and Traditional (commonly 50/50 or weighted by your tax-rate forecast confidence). Tax diversification in retirement gives you the option to drawdown from whichever bucket minimises your tax bill that year — a valuable real option worth several percent of total portfolio.
The ASEAN and APAC angle — same principles, different vehicles
Singapore's Supplementary Retirement Scheme (SRS) is structured exactly like Traditional IRA: contributions are tax-deductible (up to S$15,300/yr for citizens/PRs), growth is tax-deferred, and withdrawals after age 63 are taxed — but only 50% of withdrawals are taxable, giving SRS an effective tax rate roughly half the marginal rate. There is no Roth-equivalent in Singapore. CPF Special Account (4-5% guaranteed) is technically pre-tax-funded but withdrawals are entirely tax-free — closer to Roth in spirit. Malaysia's Private Retirement Scheme (PRS) gives RM3,000/yr tax relief — Traditional-style. Hong Kong's MPF voluntary contributions and TVC offer tax deduction up to HK$60,000/yr — Traditional. UK SIPP works exactly like Traditional with tax relief at marginal rate, taxed on drawdown (25% tax-free lump sum exemption is the "Roth-ish" element). Australia's Superannuation has unique 15% concessional tax on contributions — neither pure Roth nor pure Traditional, but closer to Traditional. The framework in this calculator applies to all: substitute your current marginal rate and expected retirement rate, the winner is determined by which is higher.
10 Things to Know About Roth vs Traditional
At equal tax rates now and in retirement, Roth and Traditional produce the exact same after-tax dollar — multiplication commutes. The "Roth grows tax-free!" sales pitch is misleading; both vehicles grow tax-free.
2025 Roth IRA contribution limit: $7,000 (+$1,000 catch-up if age 50+). Same combined limit applies across Roth and Traditional IRAs. 401(k) limit is $23,500 (+$7,500 catch-up).
Roth IRA income phase-out (2025): contributions phase out between $150K-$165K for single filers, $236K-$246K for joint. Above the upper limit you cannot contribute directly to Roth IRA — but see backdoor Roth.
Roth 401(k) has NO income limit — employees at any income can elect Roth 401(k) contributions. SECURE 2.0 also lets employer matches go into Roth (taxable that year).
Backdoor Roth: contribute $7K to non-deductible Traditional IRA, then immediately convert to Roth. Legal workaround for high earners — but only clean if you have NO existing pre-tax IRA balance (otherwise pro-rata rule applies).
Mega backdoor Roth: contribute after-tax dollars to 401(k) (up to total $70K/yr 2025 limit), then immediately in-plan convert to Roth. Requires plan support. Lets high earners stuff $40K+ extra into Roth annually.
Roth has no Required Minimum Distributions during the original owner's lifetime — major estate-planning advantage. Traditional IRAs require RMDs starting at age 73 (rising to 75 in 2033 per SECURE 2.0).
Singapore SRS = Traditional structurally: tax-deductible contributions (S$15,300/yr cap for citizens/PRs), tax-deferred growth, but only 50% of withdrawals are taxable after age 63 — making effective tax rate ~half marginal.
SECURE 2.0 (2022) requires catch-up contributions for high earners ($145K+) to be Roth starting 2026 — even if they prefer Traditional. Aims to capture more current-year tax revenue.
Tax diversification is undervalued: many practitioners split contributions 50/50 between Roth and Traditional to hedge future tax-rate uncertainty. The real option to choose withdrawal source in retirement is worth several percent of portfolio value.
Frequently Asked Questions
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Mathematically a tie — the after-tax dollar is identical. Choose based on secondary factors: Roth has no RMDs (better for estate), Roth withdrawals don't increase Social Security taxation or Medicare IRMAA, and Roth gives you a tax-free bucket for flexible drawdown. Traditional gives you a current-year tax deduction (psychologically valuable) and works better if you might have a low-income gap year (Roth conversion ladder opportunity).
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Because almost no one actually does a single one-time contribution — IRAs and 401(k)s are funded year by year, capped by annual limits. The annuity-due future-value formula correctly captures the growth path of N annual contributions. For a single lump-sum scenario, set years to your horizon and treat the contribution as if it's the first-year only (the relative comparison still holds — both Roth and Traditional respond identically to the contribution timing).
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Misleading marketing — both Roth AND Traditional grow tax-free inside the account. The difference is WHEN tax is applied (entry vs exit), not whether growth is taxed. The "Roth grows tax-free!" framing pitches a phantom benefit. The real Roth advantage is locking in today's tax rate against future rate uncertainty, plus the no-RMD treatment, plus the larger effective contribution (because $7K of Roth = $7K of post-tax money, which is more "real money" than $7K of pre-tax).
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Yes — this is a subtle but real advantage when you're contribution-limit-constrained. $7,000 of Roth = $7,000 of post-tax money. $7,000 of Traditional = $7,000 of pre-tax money, which would only be ~$5,460 if you'd taken it as cash and paid 22% tax. If you're maxing the IRA limit, Roth effectively lets you shelter more wealth. The calculator assumes you contribute the same nominal dollar amount to either — the implicit advantage to Roth in limit-constrained scenarios is real but not captured here.
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Yes — sabbaticals, early retirement years before Social Security/RMDs, gap years between jobs are excellent times to convert Traditional → Roth at low marginal rates. A 12% conversion now beats paying 24-32% later. Use a Roth conversion ladder: convert just enough each year to fill up the 12% or 22% bracket without spilling into the next. Watch out for ACA subsidy cliffs and Medicare IRMAA brackets — conversions can trigger silent surcharges.
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Legal and confirmed by the 2017 TCJA legislative history. Process: contribute $7K to a non-deductible Traditional IRA (no income limit on this), then immediately convert it to Roth (no income limit on conversions). Pro-rata rule catch: if you have ANY pre-tax IRA balance, the conversion is taxed proportionally. Clean execution requires zero pre-tax IRA balance — typically achieved by rolling existing IRAs into your 401(k) first. Some Democrats have proposed killing the backdoor; it survives as of 2025.
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SRS is structurally Traditional: deductible now (S$15,300/yr cap for citizens/PRs, S$35,700 for foreigners), tax-deferred growth, taxed on withdrawal after age 63. The Singapore twist: only 50% of withdrawals are taxable, so the effective tax rate is roughly half your marginal — making SRS very Roth-like in net outcome for moderate-income retirees. Singapore has no Roth-equivalent vehicle. CPF Special Account is closer to Roth in that withdrawals are tax-free, but contributions aren't deductible (they're mandated, not optional).
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No — it uses static rates for both periods. Tax law uncertainty is the strongest argument for tax diversification (splitting contributions). US federal rates are at historic lows; many analysts expect them to rise. SECURE 2.0 has already changed RMD ages and forced certain Roth treatments. The honest position: model 2-3 scenarios with different retirement rates (e.g., 15%, 22%, 30%) and pick a strategy that performs acceptably across all of them rather than optimising for one assumption.
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Strategy for high earners with supportive 401(k) plans. Contribute after-tax dollars to your 401(k) (above the $23,500 employee elective deferral, up to the $70,000 total 2025 limit including employer match), then immediately convert in-plan to Roth. Stuffs $30-40K+ extra into Roth annually. Requires (1) plan supports after-tax contributions, (2) plan supports in-service conversions OR in-plan Roth rollovers. Google "[your employer] 401k summary plan description" and search for "after-tax" to check.
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No. All calculation runs entirely in your browser — contribution amount, tax rates, and time horizon never leave your device. Open DevTools → Network and you'll see zero outbound requests when you press Calculate.
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