Traditional IRA Deduction Calculator 2026: Methodology, Formulas, and Sources

2026 constants used

• IRA contribution limit: $7,500
• Age-50 catch-up amount: $1,100
• Single or head of household and covered by plan: $81,000 to $91,000
• Married filing jointly and contributor covered by plan: $129,000 to $149,000
• Married filing jointly, contributor not covered, spouse covered: $242,000 to $252,000
• Married filing separately and covered by plan: $0 to $10,000

Inputs used by the calculator

• Filing status
• Age
• Modified adjusted gross income entered by the user
• Taxable compensation entered by the user
• Planned Traditional IRA contribution
• Workplace plan coverage for the contributor
• Workplace plan coverage for the spouse

The tool expects the income figure to already reflect the user’s best estimate of modified adjusted gross income. It does not build modified adjusted gross income from a full tax return.

Calculation flow

1. Set the maximum annual IRA contribution allowed based on age and compensation.
2. Cap the entered contribution at that maximum.
3. Determine which IRS phaseout range applies based on filing status and workplace plan coverage.
4. If no phaseout applies, allow a full deduction.
5. If modified adjusted gross income is below the relevant range, allow a full deduction.
6. If income is above the range, set the deductible amount to zero.
7. If income falls inside the range, calculate a proportional partial deduction.
8. Round the partial deduction up to the next $10 and apply the IRS-style $200 minimum floor when the calculation would otherwise produce a smaller positive amount.

Why the partial deduction is rounded

IRS worksheets for IRA phaseouts use rounding conventions that keep the deductible amount from showing small odd values. This calculator follows that planning logic by rounding partial deductions upward to the next $10 and applying a $200 minimum floor when a positive partial deduction would otherwise be lower.

That means the estimate is designed to feel like an IRS worksheet result rather than a raw linear percentage with cents.

Assumptions and exclusions

• The calculator is designed for planning, not filing.
• The tool does not compute modified adjusted gross income from return data.
• State tax treatment is not included.
• It does not model every specialized spousal IRA or amended-return scenario.
• The output should be checked against final IRS worksheets when filing.

Primary sources

• IRS Notice 2025-67
• IRS retirement limit announcements for 2026
• IRS IRA contribution and deduction worksheet instructions

Related pages: calculator and guide.

Update policy

We update this page when the IRS publishes the annual retirement and IRA adjustments for the new tax year or when the IRS changes worksheet instructions that affect the deduction calculation. We also revise the page if a source clarification changes how the calculator should describe the partial-deduction logic or rounding behavior.

What this methodology does not try to do

This page is intentionally narrower than full tax software documentation. It does not model every return-level interaction, every special spousal case, or every adjustment that could alter modified adjusted gross income. The goal is to make the planning logic transparent enough for a user to understand the estimate and verify the constants, not to duplicate a full return engine.