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Same contribution, different tax now vs later. See which leaves more after tax.
Same paycheck hit is the useful comparison. Traditional uses pre-tax $X, so more reaches the account. Roth uses after-tax dollars, so Roth invests $X × (1 − current tax rate) to cost the same on your paycheck. Comparison A (same dollars into the account) is shown too — it is not apples-to-apples. Educational estimate, not tax advice.
The link updates with your numbers so you can share this comparison. 2026 IRS limits are shown as a check, not a hard cap.
Traditional invests the pre-tax amount. Roth invests that amount × (1 − current tax rate). Both cost the same take-home dollars.
| Traditional | Roth | |
|---|---|---|
| Into the account / year | — | — |
| Account value (pre-tax) | — | — |
Both accounts receive the pre-tax equivalent. Roth still pays tax on those dollars now, so your paycheck shrinks more than Traditional.
Modeled as already in that account type. Converting Traditional to Roth is a taxable event and is not included.
2026 limits: 401(k)/403(b)/457/TSP employee deferral $24,500; catch-up age 50+ $8,000 (total $32,500); super catch-up ages 60–63 $11,250 (total $35,750) if the plan allows; combined employee+employer 401(k) $72,000 plus catch-up as applicable. IRA (Traditional or Roth) $7,500; catch-up 50+ $1,100 (total $8,600). Employer match is not modeled.
Next money step: project accumulation with the 401(k) Calculator or Roth IRA Calculator, then sanity-check take-home on the Paycheck Calculator. As an Amazon Associate, DynDisc earns from qualifying purchases on Picks.
Most Roth vs Traditional graphics put the same dollar amount into both accounts, then tax Traditional at withdrawal. That chart almost always crowns Roth when tax rates are equal — because it ignores that Roth already paid tax from your paycheck. For the same hit to take-home pay, Traditional invests more principal up front. This calculator’s Comparison B (same paycheck cost) is the decision frame: Traditional gets the full pre-tax contribution; Roth gets contribution × (1 − current tax rate).
Comparison A still appears so you can see the popular chart. Use it to understand the trap, not to pick an account. If A says Roth wins by a mile while B is a toss-up, you just watched the paycheck asymmetry.
Rough rule on a same-paycheck basis: if you expect a higher tax rate in retirement, Roth’s tax-free withdrawals tend to win. If you expect a lower rate later, Traditional’s deduction now tends to win — and Traditional still parks extra dollars in the market every year for the same lifestyle cost. If rates are similar, expect a close finish; Traditional’s extra principal is the tie-breaker many people underweight.
Your real rate path is uncertain: Social Security taxation, RMDs, Roth conversion ladders, state taxes, and career income all move the needle. Treat the inputs as scenarios, not prophecy. Re-run with “tax later” a few points above and below your guess.
Toggle account type to see the right employee deferral or IRA ceiling for your age, including catch-up and the ages 60–63 super catch-up when the plan allows. Limits are a check, not a hard cap in the math — if you type above the limit, the projection still runs and the note warns you. Employer match is not modeled; take the match first regardless of Roth vs Traditional preference.
High earners may face Roth-only catch-up rules at work under SECURE 2.0 — confirm with payroll. Direct Roth IRA contributions also have income phaseouts; backdoor Roth strategies are outside this tool. For contribution growth only, pair with the dedicated Roth IRA and 401(k) calculators.
No state tax, no NIIT, no early-withdrawal penalties, no conversion tax, no sequence-of-returns stress test. Returns are a constant annual rate compounded monthly for the projection. Educational estimate — not tax, investment, or legal advice.
Educational estimate only. Not tax, investment, or legal advice. Future returns, tax law, and your situation will differ. 2026 IRS figures are labeled as 2026 limits.