Net Investment Income Tax Calculator USA

Result:

Taxable Investment Income: $0

Net Investment Income Tax (3.8%): $0

Understanding Net Investment Income Tax (NIIT)

The Net Investment Income Tax (NIIT) is a 3.8% surtax on certain types of investment income for individuals whose income exceeds specified thresholds. This calculator helps determine how much tax is owed under the U.S. NIIT framework using simplified inputs and instant calculations.

What Types of Income Are Included?

NIIT applies to the following types of income:

• Interest and dividends
• Capital gains (short- and long-term)
• Rental income and royalty income
• Income from businesses involved in passive activities
• Net gains from the disposition of property (excluding non-investment property)

NIIT Thresholds by Filing Status

The tax applies if your Modified Adjusted Gross Income (MAGI) exceeds:

• $200,000 for Single and Head of Household
• $250,000 for Married Filing Jointly
• $125,000 for Married Filing Separately

How NIIT Is Calculated

NIIT is calculated as 3.8% of the lesser of:

• Your net investment income
• The excess of your MAGI over the threshold for your filing status

For example, if you're single with a MAGI of $240,000 and $60,000 in investment income, NIIT applies to $40,000, and your tax is $1,520.

Why Is This Calculator Useful?

This calculator instantly determines whether you’re liable for NIIT and how much you owe based on real-time inputs. It’s useful for investors, landlords, business owners with passive income, and anyone concerned about tax planning.

Important Tips

• NIIT is in addition to regular income tax.
• Business income is only included if it’s from a passive activity.
• Nonresident aliens are typically exempt from NIIT.

Disclaimer

This calculator is for informational purposes only. Please consult a qualified tax professional for official guidance based on your specific financial situation.