Marriage Tax Calculator
This marriage tax calculator compares what a couple would owe in US federal income tax filing as two single people against what they would owe filing jointly, revealing whether marriage triggers a penalty or a bonus. It applies the 2024 single and married-filing-jointly brackets along with the corresponding standard deductions, so the comparison reflects current law. A penalty arises when two similar high incomes are pushed together into higher joint brackets, while a bonus is common when one spouse earns much more than the other.
Formula
Difference = JointTax(I1 + I2 − 29,200) − [ SingleTax(I1 − 14,600) + SingleTax(I2 − 14,600) ]
- I1, I2
- Each spouse's gross annual income
- SingleTax
- Progressive tax using the 2024 single brackets after the single standard deduction
- JointTax
- Progressive tax using the 2024 married-filing-jointly brackets after the joint standard deduction
- Difference
- Positive = marriage penalty; negative = marriage bonus
How it works
- Enter each spouse's annual income. The calculator subtracts the single standard deduction ($14,600 for 2024) from each income, applies the 2024 single brackets separately, and adds the two tax bills to get the total they would owe unmarried.
- It then adds both incomes together, subtracts the married-filing-jointly standard deduction ($29,200 for 2024), and runs the combined taxable income through the joint brackets.
- The difference (joint tax minus separate tax) is shown: a positive number is a marriage penalty (you pay more married), and a negative number is a marriage bonus (you pay less married).
Worked example
One spouse earns $100,000 and the other earns $0, a classic single-earner household.
- Filing single: taxable income is 100,000 − 14,600 = $85,400, which yields $13,841 in tax; the second spouse owes $0, so the separate total is $13,841.
- Filing jointly: combined taxable income is 100,000 − 29,200 = $70,800, which yields $8,032 in tax.
- Difference: 8,032 − 13,841 = −$5,809.
Filing jointly saves $5,809, a marriage bonus, because the joint brackets and larger deduction absorb the single high income more cheaply.
Frequently asked questions
- When does a marriage penalty actually happen?
- A penalty typically appears when both spouses earn high and similar incomes. Combining them can push the household into higher joint brackets sooner than two separate single returns would, so the couple pays more after marriage.
- Why do single-earner couples usually get a bonus?
- When one spouse earns most of the income, marriage effectively lets that income be taxed using wider joint brackets and a doubled standard deduction. The lower-earning spouse's unused bracket space reduces the overall bill, producing a bonus.
- What tax year and filing statuses does this use?
- It uses the 2024 federal brackets and standard deductions, comparing two single filers against married filing jointly. It does not model married-filing-separately, state taxes, credits, itemized deductions, or other income types.
- Does this include credits, deductions, or state taxes?
- No. The calculator applies only the standard deduction and federal income tax brackets. Child tax credits, itemized deductions, payroll taxes, and state income taxes can all shift the real penalty or bonus and are not included here.