IRA Contribution Calculator Formula

Understand the math behind the ira contribution calculator. Each variable explained with a worked example.

Use the IRA Contribution Calculator

Formulas Used

Maximum IRA Contribution

max_contribution = magi <= phase_out_start ? base_limit : (magi >= phase_out_end ? 0 : base_limit * (phase_out_end - magi) / phase_out_range)

Catch-Up Amount (50+)

catch_up = age >= 50 ? 1000 : 0

Variables

VariableDescriptionDefault
ageYour Age35
magiModified Adjusted Gross Income(USD)120000
filing_statusFiling Status (1=Single, 2=Married)1
base_limitDerived value= age >= 50 ? 8000 : 7000calculated
phase_out_startDerived value= filing_status == 1 ? 150000 : 236000calculated
phase_out_endDerived value= filing_status == 1 ? 165000 : 246000calculated
phase_out_rangeDerived value= phase_out_end - phase_out_startcalculated

How It Works

IRA Contribution Limits

The IRS sets annual IRA contribution limits that depend on your age and income. Roth IRA contributions phase out at higher incomes.

Phase-Out Ranges (2026 estimates)

  • Single: $150,000 − $165,000 MAGI
  • Married Filing Jointly: $236,000 − $246,000 MAGI

    • If your income is below the phase-out start, you can contribute the full amount. Above the end, you cannot contribute directly to a Roth IRA.

    Worked Example

    Age 35, single, $120,000 MAGI.

    age = 35magi = 120000filing_status = 1
    1. 01Base limit for under-50 = $7,000
    2. 02Single phase-out range: $150,000 − $165,000
    3. 03MAGI $120,000 is below $150,000
    4. 04Full contribution allowed: $7,000

    Frequently Asked Questions

    What if my income is too high for a Roth IRA?

    You can use a "backdoor Roth" strategy: contribute to a Traditional IRA (non-deductible) then convert to Roth. Consult a tax professional for details.

    Can I contribute to both a 401(k) and IRA?

    Yes, the limits are separate. You can max out both. However, Traditional IRA deductibility may be limited if you have a workplace plan.

    What is the deadline for IRA contributions?

    You can contribute for the prior tax year up until the tax filing deadline (usually April 15). No extensions apply.

    Ready to run the numbers?

    Open IRA Contribution Calculator