Marriage Tax Calculator
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Both Incomes
Difference
Enter both incomes to compare filing jointly vs. filing as two singles.
This calculator provides an educational estimate only and is not tax advice. Consult a qualified tax professional for guidance specific to your situation.
The Marriage Penalty and the Marriage Bonus
Because U.S. tax brackets aren't simply doubled at every income level for Married Filing Jointly, combining two incomes on one return can result in either more total tax (a "marriage penalty") or less total tax (a "marriage bonus") than the same two people would owe filing as two single individuals. This calculator runs both scenarios side by side using this site's federal bracket data.
When a Penalty Happens
A marriage penalty tends to appear when both spouses earn similar, moderate-to-high incomes -- combining them can push more of the couple's income into higher brackets than either spouse would have hit alone.
When a Bonus Happens
A marriage bonus tends to appear when the two incomes are lopsided (one spouse earns much more than the other) -- the MFJ brackets are wider than the Single brackets, so the lower earner's income gets "absorbed" at lower marginal rates.
Why Brackets Aren't Just Doubled
Most MFJ brackets are exactly double the Single brackets at the lower end, but the top brackets (32% and up) are not -- that's the mechanical source of the penalty for high, similarly-earning dual-income couples.
You Don't Get to Choose "As Single"
This comparison is illustrative only -- a legally married couple must file as Married Filing Jointly or Married Filing Separately, never as two Single returns. This tool shows you the size of the effect, not an alternative filing option.
Worked Example
Spouse A earns $70,000 and Spouse B earns $30,000 (combined $100,000), both using the standard deduction:
- Spouse A as single ($70,000 − $14,600 = $55,400 taxable): $7,241 tax.
- Spouse B as single ($30,000 − $14,600 = $15,400 taxable): $1,616 tax.
- Sum as two singles: $7,241 + $1,616 = $8,857.
- Filing jointly ($100,000 − $29,200 = $70,800 taxable, MFJ brackets): $8,032 tax.
- Result: $8,032 is $825 less than $8,857 -- a marriage bonus of $825.
$70,000 & $30,000 Couple
- Filing Jointly: $8,032
- Sum as Two Singles: $8,857
- Marriage Bonus: $825
How This Comparison Is Built
The "filing jointly" scenario combines both incomes, subtracts the MFJ standard deduction (or your combined itemized amount), and applies the 2024 MFJ bracket table once. The "as if single" scenario applies the 2024 Single bracket table and Single standard deduction to each spouse's income independently, then adds the two resulting tax bills together. The difference between those two totals is the penalty or bonus.
A note on scope: this tool models federal income tax only, using Tax Year 2024 brackets for illustration -- it does not account for state taxes, credits (e.g. Child Tax Credit, EITC phase-outs), or Married Filing Separately, all of which can shift the real-world result.
Key Takeaways
- Lopsided Incomes Tend to Bonus: The bigger the gap between the two incomes, the more likely the couple sees a marriage bonus rather than a penalty.
- Similar High Incomes Tend to Penalize: Two similar, high earners are the classic marriage-penalty case, since the top brackets aren't simply doubled for MFJ.
- This Is Federal Income Tax Only: State taxes and tax credits can meaningfully change -- or even reverse -- the direction of this result.
- It's Illustrative, Not a Filing Choice: Married couples file as MFJ or MFS, never as two Single returns -- this comparison only measures the size of the effect.