# Married filing jointly, withholding number does not match actual tax savings

I am getting married this year (2019). My wife will not be working or bringing in any wage.

Beginning in 2020, I plan to submit a new w-4 to specify a withholding amount, with the goal of having a very small refund (I don't want to give the IRS a big interest-free loan). I've been doing some number crunching. My taxable wages are \$88,800 (gross is 94,000).

While single, I can claim a withholding of 2: 1 for myself, and 1 because I am single and hold only one job.

When I'm married, I can claim a withholding of 3: 1 for myself, 1 for being married filing jointly, and 1 for being married, holding only one job, and my spouse doesn't work.

I have tried a couple of online calculators, and each of them shows that for me, every increment in my withholding number reduces my withheld federal income tax by about \$77 a month.

However, when I compare the tax rate on my taxable income after deducting the standard deduction of \$12,000 for being single, or \$24,000 for being married, I discover that my federal income tax will be approximately \$5,218 less for the year, or \$434 less a month.

Why are these calculators predicting that I'll have \$77 less withheld a month, but running the numbers on the tax brackets for filing jointly shows a savings of \$434 a month? Is it that the calculators are not taking into account the difference between single and married-filing-jointly? Or are my calculations way off?

Here are my calculations:

..............................Single......................................Married......................................

Income Taxed: .... 88,800 - 12,000 = 76,800 ...... 88,800 - 24,000 = 64,800

First Bracket: ......... 970 ..................................... 1,940

Second Bracket: . 3,573 ..................................... 5,448

Third Bracket: ..... 8,211 ............................................ 0

Total: ..................12,606 ..................................... 7,388

Difference = 12,606 - 7,388 = 5,218

Difference Per Month = 5,218 / 12 = \$434

• Filing status and the number of allowances are two separate fields in W-4. Is \$77 the difference that one extra allowance makes for the same filing status? Because big change in withholdings comes changing the filing status, not from claiming more allowances. Commented May 10, 2019 at 18:16
• @void_ptr, that turned out to be exactly the answer that I misunderstood. If you could kindly post that as an answer, I'll happily accept and upvote it. Commented Jun 11, 2019 at 15:03