MAGI Calculator
Modified adjusted gross income — with the catch every other calculator hides: each purpose defines MAGI differently. Pick what you need it for, and the form shows exactly the add-backs that purpose's IRS or SSA worksheet lists, nothing more.
Modified AGI, by purpose
Example: $95,000 AGI with a $10,000 Roth conversion, $7,000 IRA deduction and $2,500 student loan interest → $94,500 MAGI for Roth purposes.
One name, several numbers
Take $95,000 of AGI. For Roth IRA purposes (Pub. 590-A, Worksheet 2-1), a $10,000 conversion inside it is subtracted and the $7,000 IRA deduction and $2,500 of student loan interest come back, giving $94,500. For Medicare IRMAA, the same person with $2,500 of tax-exempt interest has a MAGI of $97,500 — a different number, from a different statute, used against different brackets. Both figures are computed at build time by the same tested engine as the calculator above. That divergence is why the purpose selector comes first.
The four definitions, and where each comes from
- Traditional IRA deduction — AGI (without the IRA deduction) plus the student loan interest deduction, foreign earned income/housing exclusion, foreign housing deduction, excluded savings bond interest, and excluded employer adoption benefits. IRS Pub. 590-A, Worksheet 1-1.
- Roth IRA contribution — AGI minus conversion/rollover income, plus the traditional IRA deduction and the same five add-backs. IRS Pub. 590-A, Worksheet 2-1.
- ACA premium tax credit — AGI plus tax-exempt interest, untaxed Social Security benefits, and excluded foreign earned income/housing. Instructions for Form 8962, Worksheet 1-1.
- Medicare IRMAA — AGI plus tax-exempt interest, nothing else. SSA POMS HI 01101.010, implementing § 1839(i) of the Social Security Act.
Your starting AGI is what the income tax math runs on after deductions — see the Take-Home Pay Calculator for how it forms from a salary, the Self-Employment Tax Calculator for the ½ SE-tax deduction that reduces it, and the Tax Bracket Calculator for where it lands you.
Frequently asked questions
Why does the calculator make me pick a purpose?
Because "MAGI" is not one number. Each provision of the tax code defines its own modified AGI: the IRA rules add back deductions like student loan interest, the ACA premium credit adds untaxed Social Security, and Medicare IRMAA adds only tax-exempt interest. A calculator that showed a single "MAGI" would be quietly wrong for most uses — the purpose selector is the honest design.
Where do these add-back lists come from?
Each list is taken from the controlling worksheet: IRS Publication 590-A, Worksheet 1-1 (traditional IRA) and Worksheet 2-1 (Roth IRA); the IRS Instructions for Form 8962, Worksheet 1-1 (ACA premium tax credit); and the Social Security Administration’s POMS section HI 01101.010 with section 1839(i) of the Social Security Act (Medicare IRMAA). Nothing here is a blogger’s summary.
Why is Roth conversion income subtracted?
Converting a traditional IRA to a Roth adds the converted amount to your AGI, but Publication 590-A’s Worksheet 2-1 removes it again for Roth contribution purposes — otherwise a conversion could artificially push you over the contribution limit. It is the only subtraction in any of these definitions, and it applies only to the Roth purpose.
Which AGI do I start from for the traditional IRA purpose?
Your AGI figured WITHOUT the IRA deduction itself — Worksheet 1-1 is testing whether you may take that deduction, so it cannot start from a number that already includes it. For every other purpose, start from your actual AGI (Form 1040, line 11).
Does this tell me whether I can contribute, or what my premium will be?
No — deliberately. The phase-out ranges, credit tables, and IRMAA brackets change every year and belong to each program’s own published tables. This tool computes the MAGI those tables are compared against; check the current thresholds on IRS.gov (IRA phase-outs), HealthCare.gov (premium credit), or SSA.gov/Medicare (IRMAA brackets).
Which year is IRMAA MAGI from?
Generally your return from two years before the premium year — 2026 premiums usually rest on your 2024 return (SSA uses the most recent return the IRS can provide, up to three years back). The other purposes use the current tax year’s figures.
Not tax advice: this tool computes the MAGI figure for the selected purpose only — it does not evaluate IRA phase-out ranges, premium-credit eligibility, or IRMAA brackets, which change annually and are published by the IRS, HealthCare.gov, and SSA respectively. Rarer worksheet refinements (such as Pub. 590-A’s note on refiguring AGI when other phaseouts interact, or Form 8962’s dependent and Form 8814 special cases) are not modeled. Consult a tax professional for your situation. Values are processed locally in your browser and never transmitted. See the methodology page.