Hong Life CalculatorsUnderstanding the MAGI calculator — concept and principle
Modified adjusted gross income (MAGI) is the income figure the IRS uses to decide whether you can contribute to a Roth IRA, deduct a traditional IRA contribution or claim the ACA premium tax credit. This calculator builds MAGI from your AGI for the purpose you pick and checks where you stand against the 2026 phase-out range.
How it is calculated
MAGI = AGI (Form 1040 line 11) + add-backs − subtractions. The add-backs depend on the purpose:
- Roth IRA: add the IRA deduction, student loan interest deduction, excludable savings bond interest, employer adoption benefits and foreign earned income or housing exclusions; subtract Roth conversion or rollover income.
- Traditional IRA deduction: the same add-backs, without the subtraction.
- ACA premium tax credit: add excluded foreign earned income, tax-exempt interest and untaxed Social Security benefits.
Inside a phase-out range the allowed amount falls in proportion: limit × (end − MAGI) ÷ (end − start). The 2026 IRA limit is 7,500 USD, or 8,600 USD at age 50 or older.
The principle
AGI already subtracts some deductions. For certain benefits, Congress wanted to measure a broader income, so MAGI adds back items that would otherwise make income look lower. The phase-out then reduces the benefit gradually instead of cutting it off at one income level. 2026 Roth ranges are 153,000–168,000 USD for single or head of household and 242,000–252,000 USD for joint filers.
Worked example
Default inputs: Roth IRA, single, under 50, AGI 160,000 USD, student loan interest deduction 2,500 USD, all other items 0.
- Add-backs = 2,500 USD; subtractions = 0 USD.
- MAGI = 160,000 + 2,500 = 162,500 USD.
- The single Roth phase-out runs from 153,000 to 168,000 USD, so you are inside the phase-out range.
- Allowed = 7,500 × (168,000 − 162,500) ÷ 15,000 = 2,750 USD.
| Adjusted gross income, Form 1040 line 11 (USD) | Modified AGI, MAGI (USD) |
|---|---|
| 40,000 | 42,500 |
| 80,000 | 82,500 |
| 120,000 | 122,500 |
| 160,000 | 162,500 |
| 200,000 | 202,500 |
| 240,000 | 242,500 |
| 320,000 | 322,500 |
How to read the result
Below the start of the range you can contribute the full limit; above the end, nothing directly to a Roth (a backdoor conversion is a separate strategy). The IRS worksheet rounds the reduced limit, so your exact figure may differ by a few dollars. Married filing separately has a very narrow range that starts at zero.
Common mistakes
- Using total income or wages instead of AGI from line 11.
- Applying the Roth formula to the ACA credit, which uses different add-backs.
- Using last year's phase-out ranges.
- Forgetting that contributions are also limited to your taxable compensation.
Frequently asked questions
What is the Roth IRA income limit for 2026?
For single filers the phase-out is 153,000–168,000 USD of MAGI; for joint filers 242,000–252,000 USD.
Is MAGI the same as AGI?
Often they are close or equal, but MAGI adds back specific items that depend on the tax benefit.
Does a Roth conversion count toward MAGI for Roth limits?
No. Conversion income is subtracted when computing MAGI for Roth contribution limits.
Sources: IRS Publication 590-A, Contributions to Individual Retirement Arrangements (MAGI worksheets) · IRS, 2026 retirement plan limits announcement (IRA contribution limits and phase-out ranges)