Roth IRA Calculator

Roth vs Traditional

Both accounts let your money grow tax-free, but they tax it at different times:

Roth: contribute after-tax, withdraw tax-free in retirement.
Traditional: contribute pre-tax (lowers today's tax bill), withdraw and pay ordinary income tax in retirement.

The fair comparison

If you put $7,500 into a Roth, you spent $7,500 after-tax. Putting the same $7,500 into a Traditional IRA only costs you $5,850 after-tax (at a 22% bracket). To compare them fairly, the Traditional version should contribute the pre-tax equivalent — about $9,615/yr — so out-of-pocket cost is equal.

The "Traditional (after tax)" row above shows the fair comparison: pre-tax contributions grown to retirement, then taxed at withdrawal.

Which wins?

Same tax rate now and in retirement? They tie mathematically.
Tax rate higher in retirement? Roth wins (you locked in today's lower rate).
Tax rate lower in retirement? Traditional wins (you deferred at a higher rate).

The formula

B_y = B_y−1 × (1 + r) + C

Each year's balance is last year's balance grown by the return rate, plus that year's contribution, compounded annually with the contribution landing at year-end. Over n years starting from B₀, that unrolls to the standard annuity future-value formula:

FV = B₀(1 + r)ⁿ + C · ((1 + r)ⁿ − 1) / r

The "fair" Traditional side runs the same formula on a pre-tax contribution of C / (1 − t_now) — since that costs the same out of pocket as a Roth contribution of C — then applies (1 − t_retirement) once, at withdrawal.

Worked example

$0 starting balance, $7,500/year (the 2026 maximum), age 30 to 65 (35 years), 7% return, 22% marginal tax bracket now and in retirement:

Total contributed: 35 × $7,500 = $262,500
Roth balance at 65: $1,036,777 (growth of $774,277)
Fair Traditional, after tax at withdrawal: also $1,036,777

Same rate now and later lands on the exact same number — that's the tie case, not a rounding coincidence. Retire into a lower bracket instead and Traditional pulls ahead: at a 12% retirement rate the same contributions leave $912,363 after tax on the same-contribution comparison, against the Roth's $1,036,777. Retire into a higher one — 24% — and the Traditional side falls to $787,950. The account type doesn't change your return; it changes when the IRS gets paid.

Frequently asked questions

What's the 2026 Roth IRA contribution limit?

$7,500 if you're under 50, $8,600 if you're 50 or older — the $1,100 catch-up is the first cost-of-living increase to the catch-up amount, per IRS Notice 2025-67. That limit is shared across Traditional and Roth IRAs combined, not per account.

Can I contribute if my income is too high?

Direct Roth contributions phase out between $153,000 and $168,000 of modified AGI for single filers, and $242,000 to $252,000 for married filing jointly, for 2026. Above the top of that range you can't contribute directly — a "backdoor Roth" conversion is the common workaround, but this calculator doesn't model conversions.

Can I take money out of a Roth before retirement?

Contributions (not earnings) can be withdrawn any time, tax- and penalty-free, since you already paid tax on that money. Earnings withdrawn before age 59½ and before the account is 5 years old generally trigger a 10% penalty plus income tax on the earnings portion. This calculator assumes the money stays invested for the full horizon — it's pure accumulation math, not a withdrawal planner.

Does this account for required minimum distributions?

No, and for the Roth side it doesn't need to — original Roth IRA owners have no RMDs under current law, at any age. A real Traditional IRA would face RMDs starting at 73 or 75 depending on birth year, which this simplified comparison doesn't model.