Retirement calculator

Free roth ira vs traditional ira calculator

Compare the after-tax value of a Roth (pay tax now) against a Traditional IRA (pay tax later) for your own tax rates — updated live, as you type.

On this page12 sections

InputsLive

Current age

years

Current savings (invested)

Annual income

Annual expenses

Real return

Safe withdrawal rate

Result

Age at financial independence

45.4

The age you reach financial independence — about 15.4 yrs from now, once your portfolio hits $1,000,000.

FIRE number$1,000,000

Savings rate50%

Years to FI15.4 yrs

Estimates only, based on a constant real return and steady saving. Not financial advice.

Results are estimates. Consult a professional.

The decision

Roth IRA vs. Traditional IRA: pay tax now or later?

The Roth IRA vs. Traditional IRA choice comes down to one question: do you want to pay tax on this money now or later? A Roth IRA takes after-tax dollars today and pays out tax-free in retirement; a traditional IRA deducts your contribution today and taxes the withdrawal later. This calculator settles the tie by comparing the after-tax value of each side, so you compare apples to apples. Enter an amount, your tax rate now, your expected tax rate in retirement, a return, and a time horizon — it names the winner live as you type.

The single deciding factor is how your tax rate now compares with your tax rate in retirement. If your retirement tax rate will be higher, Roth wins. If it will be lower, Traditional wins. If the two rates are identical, the after-tax results are mathematically the same — a tie.

What you actually keep after all tax is paid — the only fair basis for comparing a Roth (taxed now) with a traditional IRA (taxed later).

Your marginal tax rate today, which a Roth contribution is effectively taxed at (you contribute after-tax dollars).

The marginal rate you expect when withdrawing — what a traditional IRA's withdrawal is taxed at.

When the two tax rates are equal, both accounts produce the same after-tax balance.

The method

How the after-tax comparison is calculated

Both sides start from the same amount and grow at the same return for the same number of years. The difference is purely when the tax is applied — at the front for the Roth, at the back for the traditional.

Roth after-tax = amount × (1 − tax rate now) × (1 + r)^years

Traditional after-tax = amount × (1 + r)^years × (1 − tax rate later)

Winner = whichever after-tax value is higher

This model compares a lump sum taxed once on each side — the clean way to isolate the now-vs-later tax question. It does not add the separate advantage that a deductible traditional contribution frees up cash today, which, if invested, narrows the gap.

Inputs

How to use the inputs

Amount available. The sum you are deciding how to place — for a like-for-like comparison, the same pre-tax amount on both sides.
Current tax rate. Your marginal rate today; this is what the Roth side effectively pays upfront.
Withdrawal tax rate. The marginal rate you expect in retirement; this is what the traditional side pays at the end. This is the lever that decides the winner.
Annual return. The growth rate applied equally to both sides — it scales both, so it changes the size of the gap but not which side wins.
Years until withdrawal. The compounding horizon, again applied to both sides.

Worked example

A worked example: when Roth wins

Example: 22% now, 32% in retirement

Sam compares $100,000 over 20 years at a 7% return, expecting a 22% tax rate today but a higher 32% rate in retirement (a rising income or higher future tax rates). These are the calculator's inputs, so you can reproduce the result.

Step 1 — Grow both sides

$100,000 at 7% for 20 years grows to about $386,968 pre-tax. Both accounts reach the same pre-tax figure; only the tax timing differs.

Step 2 — Apply tax at the right time

Roth: 100,000 × (1 − 0.22) × 1.07^20 = $301,835

Traditional: 100,000 × 1.07^20 × (1 − 0.32) = $263,139

Step 3 — Read the winner

Roth wins by $38,697

Roth nets $301,835 vs. the traditional IRA's $263,139. Because Sam's retirement tax rate (32%) is higher than today's (22%), paying tax now wins. These are the figures this calculator returns for those inputs.

Flip the rates and the answer flips too. If Sam expected 32% now and only 22% in retirement, the traditional IRA wins by the same $38,697 — netting $301,835 against the Roth's $263,139. The size of the gap is identical because the tax-rate difference is identical; only its direction changes.

Reference

Roth vs. Traditional IRA at a glance

Feature	Roth IRA	Traditional IRA
Contributions	After-tax (no deduction)	Often pre-tax / deductible
Withdrawals	Tax-free if qualified	Taxed as ordinary income
Tax break timing	Later (in retirement)	Now (this year)
Required minimum distributions	None during owner's life	Begin at age 73
Income limit to contribute	Yes — MAGI phase-out	None to contribute
Best when	Retirement tax rate ≥ today's	Retirement tax rate < today's

2025 contribution cap is the same for both: $7,000, or $8,000 if age 50+, combined across all IRAs. Source: IRS.

IRS — Retirement topics: IRA contribution limits (shared 2025 cap $7,000 / $8,000).

Rules of thumb

Which IRA wins for your situation

Roth tends to win for younger or lower-income savers now who expect higher earnings or higher tax rates later, and for anyone who values tax-free withdrawals and no RMDs.
Traditional tends to win for peak earners who expect a lower retirement bracket and want the deduction today.
It is roughly a tie when your tax rate barely changes — in which case secondary factors (RMDs, estate planning, current cash flow) break the deadlock.
Splitting both hedges the bet: tax diversification means you can pull from whichever account is most tax-efficient in a given retirement year.

Dig into either side with the dedicated Roth IRA calculator and Traditional IRA calculator, or project total IRA growth with the general IRA calculator.

Mistakes to avoid

Mistakes when comparing Roth and Traditional

Comparing balances instead of after-tax values. A traditional IRA's balance looks bigger only because the tax has not been paid yet. Always compare what you keep.
Guessing your retirement tax rate too low. RMDs, Social Security, and pensions can push retirement income — and your bracket — higher than expected, which favors the Roth.
Ignoring the deduction's reinvested value. If you actually invest the tax a traditional deduction saves you today, the traditional side does better than the lump-sum model alone shows.
Overlooking RMDs. Traditional IRAs force taxable withdrawals at 73; Roth IRAs do not, which matters if you do not need the money.

Methodology

How this calculator works and accuracy

This Roth vs. Traditional IRA calculator grows the same amount at the same return on both sides and applies your current tax rate to the Roth and your retirement tax rate to the traditional, then names the higher after-tax result. It compares a single lump sum and does not separately reinvest the traditional deduction or model RMDs, so treat the output as a planning estimate, not a guarantee or financial advice. The shared 2025 contribution cap cited here comes from the IRS.

IRS — Retirement topics: IRA contribution limits (2025 $7,000 / $8,000 catch-up, shared across IRAs).IRS — RMD FAQs (traditional IRA RMDs begin at 73; Roth IRAs exempt during the owner's life).

Questions

Frequently asked questions about the free roth ira vs traditional ira calculator

A roth IRA vs Traditional IRA calculator is a free online tool that helps you compare after-tax retirement value of Roth (pay tax now) vs Traditional (pay tax later). Roth wins if your retirement tax rate is higher than current. Traditional wins if lower. It runs entirely in your browser with instant results and no sign-up.

It comes down to your tax rate now versus in retirement. If your retirement tax rate will be higher, the Roth wins because you pay tax today at a lower rate. If it will be lower, the traditional IRA wins because you deduct at a high rate now and withdraw at a lower one. If the rates are equal, the after-tax results are identical.

Because the math is just multiplication, and multiplication does not care about order. Taxing money at the front (Roth) or at the back (traditional) gives the same after-tax result when the tax rate is the same both times. The two accounts only diverge when your current and retirement tax rates differ.

Splitting is a reasonable hedge when you are unsure how your future tax rate will compare. Holding both gives you tax diversification, so in retirement you can draw from whichever account is most tax-efficient in a given year. Your total across both still cannot exceed the combined $7,000 ($8,000 if 50+) 2025 limit.

This lump-sum model does not. It compares the same amount taxed once on each side to isolate the now-versus-later question. In practice, if you invest the cash a deductible traditional contribution frees up today, the traditional side does somewhat better than the pure comparison shows.

They can. A traditional IRA forces taxable required minimum distributions starting at age 73, which can push your retirement income — and tax bracket — higher and tilt the math toward the Roth. A Roth has no RMDs during the owner's lifetime, so it favors anyone who does not need to spend the money.

About

About this Roth IRA vs Traditional IRA calculator

This calculator compares the after-tax value of a Roth IRA against a traditional IRA so you can decide whether to pay tax now or later. Both sides grow the same amount at the same return for the same horizon; the only difference is when tax applies — at the front for the Roth, at the back for the traditional. The winner turns entirely on whether your retirement tax rate is higher or lower than today's.

It compares a single lump sum and is a planning estimate, not financial advice. Dig into either account on the rest of the retirement calculators shelf, or browse every tool in the calculator directory.