NIIT Calculation

[daver]

We use irscalculators.com to estimate our taxes in December. As for the net investment income tax (NIIT) calculation, it seems the calculator only applies the 3.8% tax to the dollar amount over the $250K MFJ Threshold. In our case our net investment income (interest and dividends only) is lower than the amount by which we exceeded the $250K threshold, so the tax should apply to that lesser NII amount.

Just wondering if anyone that uses irscalculators.com has a workaround for this?

 

[SecondCor521]

I would try a different tax estimation calculator.

Does the Case Study Spreadsheet on MDM work for you? It handles a lot of stuff:

Case Study Spreadsheet updates

Case Study Spreadsheet updates

forum.mrmoneymustache.com

It's what I use and handles my relatively complicated situation. The author / maintainer, MDM, is pretty responsive to bug reports.

 

[Midpack]

Most accurate I’ve found 1040 Tax Calculator

 

[SevenUp]

I would try a different tax estimation calculator.

Does the Case Study Spreadsheet on MDM work for you? It handles a lot of stuff:

Case Study Spreadsheet updates

Case Study Spreadsheet updates

forum.mrmoneymustache.com

It's what I use and handles my relatively complicated situation. The author / maintainer, MDM, is pretty responsive to bug reports.

+1

That spreadsheet has matched our official filing to the dollar. Other tools would also do so for those who don't use Excel, but the chart the spreadsheet generates showing where the marginal rate changes seems unique among commonly recommended tools. Of course, any result will only be as good as the inputs, so surprise capital gain distributions, etc., will affect all estimates.

For most people, the definition of "best" is "the one we have used and are familiar with" and our opinion is no different.

 

[daver]

Most accurate I’ve found 1040 Tax Calculator

Yes that calculator correctly determines the NIIT rule below.

Thanks....

"If you have investment income and go over the MAGI threshold, the 3.8% tax will apply to your net investment income or the portion of your MAGI that goes over the threshold—whichever is less."