Marriage Tax Calculator

Penalty and bonus are the same mechanism

There is no separate marriage tax. The difference comes from the shape of the brackets: for most of the schedule the married-filing-jointly band is exactly twice the single band, so two equal incomes pay the same either way. Where the joint band is less than twice the single band — at the top of the schedule — two high earners are pushed into a higher rate by marrying, and that is the penalty. Where the incomes are unequal, joint filing averages them across the lower bands and produces a bonus. One spouse earning nothing produces the largest bonus of all.

Why the two-single figure is the honest comparison

The alternative to filing jointly is not filing separately — married filing separately uses the narrowest brackets of all and is almost always worse. The real counterfactual is the two returns you would each have filed had you not married, which is what the middle line computes: each income with its own single-filer brackets and its own standard deduction.

What this covers and what it does not

This is federal income tax on wages: brackets, the standard deduction, and the child tax credit at $2,000 per child. It does not model payroll tax — Social Security and Medicare are withheld per person regardless of marital status, so they cancel out of the comparison — and it does not model state tax, which has its own bracket shapes and can flip the answer in either direction. Itemized deductions, capital gains, phase-outs of credits and the alternative minimum tax all sit outside this page.

The timing rule people miss

Marital status for the whole tax year is set by your status on 31 December. A wedding on the 30th means you file as married for the entire year just gone; a divorce final on the 30th means you file as single for a year you spent married. Where the number above is large, that date is worth a conversation — and where it shows a bonus, a December wedding claims a full year of it.

Two earners, one bracket

A practical consequence of joint filing: the second income stacks on top of the first, so its first dollar is taxed at the rate the first income has already reached, not at 10%. Couples are routinely surprised by a bill at filing time because both employers withheld as though their salary were the household's only one. The joint marginal rate above is the rate that applies to the next dollar either of you earns — adjust withholding to that figure rather than to the effective rate.

Frequently Asked Questions