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NIIT Calculator

Calculate the 3.8% Net Investment Income Tax — a surtax on interest, dividends, capital gains, and other investment income once your MAGI crosses the IRS threshold for your filing status.

Quick answer: Estimate the 3.8% NIIT on the lesser of entered net investment income or MAGI above the filing-status threshold. Enter Modified Adjusted Gross Income (MAGI), Net Investment Income, and Filing Status to personalize the estimate. It returns NIIT Owed, MAGI Threshold for Your Status, and MAGI Above Threshold so you can compare the impact before choosing a next step. Use it to estimate tax impact, withholding, deduction, bracket, and after-tax cash-flow tradeoffs.

NIIT Owed
$760
NIIT Owed
$760
MAGI Threshold for Your Status
$200,000
MAGI Above Threshold
$20,000
Amount Subject to NIIT
$20,000
Diagnostic

NIIT only applies to the lesser of your net investment income or the amount your MAGI exceeds $200,000 — that's $20,000 here.

At 3.80%, you owe about $760 in Net Investment Income Tax.

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What to do next

Plan your tax strategy ->

Your action plan
  1. 1

    Set the target and timeline for this plan

    Estimate the 3.8% NIIT on the lesser of entered net investment income or MAGI above the filing-status threshold.

  2. 2

    Check the assumptions before using the result for a high-stakes decision

    Assumptions change the answer, especially when rates, taxes, or timing matter.

  3. 3

    Save the result to Money Map or use the linked next action

    Turn the result into a prioritized action instead of treating it as a one-off number.

Plan your tax strategy

This is an educational estimate, not tax, legal, investment, or lending advice. Confirm with a qualified professional or the provider before acting.

Calculator action path

Turn this result into a decision

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Guide
Self-Employed Taxes Explained: What You Owe and How to PaySelf-employed workers pay self-employment tax (Social Security + Medicare) plus income tax, and must send quarterly estimated payments or face penalties. Here's the full picture for freelancers, contractors, and sole proprietors.
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Frequently Asked Questions

Everything you need to know.

What does the NIIT Calculator show?
Calculate the 3.8% Net Investment Income Tax — a surtax on interest, dividends, capital gains, and other investment income once your MAGI crosses the IRS threshold for your filing status.
How should I use the result?
Use the result as a planning and comparison aid. Review the assumptions, adjust your inputs, and compare the output with your actual options before acting.
What should I do after using this calculator?
Use the related links and next-action modules on the page to compare products, continue in Money Map, or review related guidance on SwitchWize.
Is the NIIT Calculator free to use?
Yes. SwitchWize calculators are free, and you do not need an account to run scenarios or view the result.
Does using the NIIT Calculator affect my credit score?
No. Using a calculator does not trigger a credit check. A credit impact can occur only if you apply directly with a lender, card issuer, or provider.
Are the results personalized financial advice?
No. Calculator outputs are educational estimates based on the inputs you enter. Review assumptions and confirm terms directly with providers before making a financial decision.
What should I do after seeing the result?
Use the recommendation module on this page to plan your tax strategy ->, or run Money Map to compare this taxes decision with your other opportunities.
How does SwitchWize choose related offers?
Related offers are matched by the calculator surface (taxes) and ranked using SwitchWize data such as rate, fees, trust signals, product fit, and switching friction. Paid relationships do not change organic ranking order.
How fresh are the rates and offers shown?
Rate and offer data is reviewed on a recurring cadence and every offer module shows review context or links to the methodology and disclosure pages.
Where can I see the ranking methodology?
The SwitchWize methodology page explains how rate freshness, editorial review, affiliate disclosure, and category ranking factors work.
Can Money Map use this result?
Yes. Money Map is the broader diagnostic path: it compares savings, mortgage, cards, and debt so you can see whether this calculator result is your highest-impact next move.

Why This Matters

NIIT Calculator helps users make a taxes decision with clearer numbers, assumptions, and next actions.

How to Use It

  1. 1Enter your numbers in the input panel.
  2. 2Review the live results and interpretation on the right.
  3. 3Use the goal outputs to compare options or plan the next step.
  4. 4Use the related links below if you want to move from analysis to action.
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Plan your tax strategy ->