NIIT Calculator (2026)
The 3.8% Net Investment Income Tax hits high earners with investment income above $200,000 (single) or $250,000 (joint). See if it applies to you and how much it costs.
How to use this calculator
- Enter net investment income.
- Enter mAGI (modified adjusted gross income).
- Enter filing status.
- Your results appear instantly below and update as you change the numbers.
How this calculator works
The NIIT is 3.8% of the smaller of two numbers: your net investment income (interest, dividends, capital gains, rents, passive business income) or the amount your MAGI exceeds $200,000 (single) / $250,000 (joint). Worked example: $12,000 of investment income and $260,000 MAGI as a joint filer — MAGI is $10,000 over the threshold, so $10,000 is taxed at 3.8% = $380, on top of your regular income tax.
Frequently asked questions
Does the NIIT apply to wages?
No — wages, salaries, self-employment income, and taxable IRA distributions are not net investment income. But wages can push your MAGI over the threshold, which makes your investment income subject to the tax. That is why a high salary plus dividends or capital gains is the classic NIIT trigger.
Are municipal bond interest and Roth withdrawals taxed?
No — tax-exempt interest and qualified Roth distributions are excluded from net investment income. This is one reason munis and Roth accounts are attractive to high earners who would otherwise pay the surcharge.
How do I reduce NIIT?
Reduce MAGI below the threshold or shrink net investment income: max out pre-tax 401(k)/IRA contributions, harvest capital losses to offset gains, invest in tax-exempt bonds, use rental losses, or defer gains. Charitable giving and QCDs also lower MAGI directly.
What is the 2026 threshold?
$200,000 of MAGI for single filers and $250,000 for married filing jointly (the same as it has been since 2013 — the thresholds are not inflation-adjusted).
Disclaimer: Results are estimates for general information only and do not constitute financial, tax, or legal advice. Figures reflect 2026 rules and may change. Always confirm current limits and consult a qualified professional before making decisions. Official figures: IRS.gov · 2026 limits per IRS tax inflation adjustments.