Net Investment Income Tax Calculator

Net Investment Income Tax Calculator. An investor enters modified AGI, the NIIT threshold, net investment income, and a 3.8% style rate to estimate the net-investment-income-tax base. Use it when investment income and modified AGI may exceed the applicable threshold.

Inputs

Note

Investments & Capital Gains inputs

Modified adjusted gross income ($)

Range: 0–100,000,000 $

Enter a non-negative US-dollar amount for the stated tax year; use the same tax year and jurisdiction for all related inputs. Professional example: 250000. Edit this value for your own facts.

NIIT threshold for filing status ($)

Range: 0–100,000,000 $

Enter a non-negative US-dollar amount for the stated tax year; use the same tax year and jurisdiction for all related inputs. Professional example: 200000. Edit this value for your own facts.

Net investment income ($)

Range: 0–100,000,000 $

Enter a non-negative US-dollar amount for the stated tax year; use the same tax year and jurisdiction for all related inputs. Professional example: 30000. Edit this value for your own facts.

NIIT rate (%)

Range: 0–100 %

Enter a percentage as a whole number, such as 22 for 22%, not 0.22. Professional example: 3.8. Edit this value for your own facts.

Result

Excess Magi

50,000.00

Net investment income tax (NIIT)

1,140.00

Estimate

Niit Base

30,000.00

How to interpret this result

Net Investment Income Tax Calculator starts with a professional planning example for this scenario. Edit the inputs to replace the example with your own facts; the displayed outputs update from the formula.

Applicability and limits

This is a simplified threshold calculation. It does not determine MAGI, filing-status thresholds, material-participation exclusions, business-income treatment, or Form 8960 adjustments.

Calculation basis

Only the named inputs and displayed formula relationships are used. Rates, limits, thresholds, eligibility flags, dates, and jurisdiction assumptions are not silently looked up unless a verified dataset is listed.

Formula

Calculation logic

Formula definitions and substituted values.

What to check

An investor enters modified AGI, the NIIT threshold, net investment income, and a 3.8% style rate to estimate the net-investment-income-tax base.
Use it when investment income and modified AGI may exceed the applicable threshold.
This is a simplified threshold calculation. It does not determine MAGI, filing-status thresholds, material-participation exclusions, business-income treatment, or Form 8960 adjustments.