📈 Roth IRA Calculator: Contribution Limit, Income Phase-Out and Growth

Roth IRA contribution calculator

Results

Roth IRA income phase-out explained: as MAGI moves from the phase-out start to the phase-out end, the allowed contribution falls from the full limit to zero.

How the phase-out and growth work

Calculation method and formula

Roth IRA catch-up contribution age 50 and older is added to the base limit before the phase-out.

The Roth IRA contribution calculator uses candidate rules from the prompt and your editable rule inputs. The phase-out fraction is rounded to three decimals, the reduced limit is rounded up to the next $10, and a $200 minimum applies when the reduced limit is above $0 but below $200.

allowedBefore = min(baseLimit + (age >= 50 ? <= phaseOutStart: maximum = allowedBefore
if MAGI >= phaseOutEnd: maximum = 0
fraction = round3((MAGI - phaseOutStart) / (phaseOutEnd - phaseOutStart)), capped at 1
reduction = allowedBefore x fraction
reduced = allowedBefore - reduction
maximum = roundUpTo10(reduced); if 0 < maximum < 200 then maximum = 200

monthlyContribution = plannedAnnual / 12, or the monthly amount you entered
i = annualReturn / 100 / 12
n = years x 12
end of month: FV = balance x (1 + i)^n + monthlyContribution x ((1 + i)^n - 1) / i
beginning of month: FV = balance x (1 + i)^n + monthlyContribution x ((1 + i)^n - 1) / i x (1 + i)
if i = 0: FV = balance + monthlyContribution x n

Money is calculated in dollars and cents. Growth values use standard double-precision arithmetic and are displayed half-up to the cent.

Worked examples you can reproduce

These examples use the candidate 2026 figures and are labeled hypothetical. They test arithmetic, not law.

Common mistakes

• Using gross income instead of modified adjusted gross income.
• Forgetting that the catch-up amount is added before the income phase-out.
• Rounding the reduced limit down instead of up to the next $10.
• Ignoring the taxable compensation cap.
• Treating a candidate or unverified limit as an IRS guarantee.
• Roth IRA excess contribution consequences are not calculated here; see IRS guidance.

Comparison tables

Candidate 2026 income phase-out ranges by filing status

Contribution timing comparison

The beginning-of-month figure is calculated by the tool when you change the timing input; the placeholder above is intentionally not stated as an official figure.

Frequently asked questions

Glossary

Modified adjusted gross income (MAGI)

The income measure used to apply the Roth IRA phase-out. The IRS defines the adjustments in Publication 590-A.

Modified adjusted gross income for Roth IRA purposes is defined by the IRS in Publication 590-A.

Phase-out

The income range over which the maximum contribution is reduced from the full limit to zero.

Taxable compensation

Earned income that can support an IRA contribution under the candidate rule.

Catch-up contribution

An additional amount allowed for savers age 50 or older under the candidate rule.

Qualified distribution

A distribution that meets the age and five-tax-year conditions in IRS Publication 590-B.

These are starting points to verify.

• IRS: Roth IRAs
• IRS: find Publication 590-A and Publication 590-B
• IRS Notice 2025-67 (candidate source for 2026 limits)
• IRS: about Form 8606
• SEC Investor.gov

Last updated: 2026-10-18.

Review owner: Varnda Editorial Team. Correction channel: use the site's normal correction process; no email address or contact form is invented here.

Limitations, exclusions, and assumptions

• Direct Roth IRA contributions only. Excludes conversions, backdoor strategies, mega backdoor, Roth 401(k), inherited IRAs, excess-contribution corrections, and state taxes.
• Spousal IRA combined-compensation rules are not modeled unless you verify and add them.
• The married filing separately branch is disabled because it is not verified.
• Projected growth uses a constant assumed return, no fees, no taxes inside the account, and no change in contribution limits over time.
• Qualified distribution rules are informational and sourced, not computed.
• Candidate 2026 figures are defaults, not verified IRS facts.

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