Marriage Tax Calculator
Calculate whether marriage creates a federal income tax bonus or tax penalty by comparing joint filing vs. two single filers under 2026 IRS tax brackets.
How It's Calculated
Formula
\text{Tax Difference} = \text{Joint Tax} - (\text{Spouse 1 Single Tax} + \text{Spouse 2 Single Tax})A marriage tax penalty or bonus occurs when a married couple pays more or less federal income tax filing jointly than they would if they were unmarried and each filed as a single taxpayer. When spouses have highly unequal earnings, joint brackets allow the higher earner's income to be taxed at lower rates (marriage bonus). Conversely, at high income thresholds where joint brackets are less than double single brackets, a marriage penalty can occur.
Worked Examples
Unequal Earners: $120,000 + $30,000 gross incomes
- Spouse 1 Single Tax: taxable income = $120,000 - $16,100 standard deduction = $103,900; single tax liability ≈ $17,046.
- Spouse 2 Single Tax: taxable income = $30,000 - $16,100 standard deduction = $13,900; single tax liability ≈ $1,424.
- Combined Single Taxes = $17,046 + $1,424 = $18,470.
- Joint Filing: combined taxable income = $150,000 - $32,200 standard deduction = $117,800; joint tax liability ≈ $15,640.
- Difference = $15,640 - $18,470 = -$2,830 (Marriage Bonus of $2,830).
Frequently Asked Questions
What causes a marriage tax bonus?
A marriage bonus typically occurs when one spouse earns significantly more than the other (or when one spouse does not work). When filing jointly, the higher earner's income fills up the lower tax brackets and standard deduction contributed by the lower-earning spouse, pulling income out of higher marginal brackets.
What causes a marriage tax penalty?
A marriage penalty can occur when two high earners have similar incomes that push their combined income into the top 37% bracket, where the joint threshold is lower than two single thresholds combined, or when income phaseouts affect deductions and credits.
Can married couples choose to file as Single?
No. Legally married couples under IRS rules must choose between Married Filing Jointly (MFJ) or Married Filing Separately (MFS). They cannot file as Single. This calculator compares MFJ against Single solely to demonstrate the structural marriage penalty or bonus of the tax code.