PersonalCFO

Marriage Penalty/Bonus Calculator

Compare your tax bill as a married couple filing jointly vs. two single returns. See the exact dollar amount of your marriage penalty or bonus, including federal income tax, FICA, and state taxes.

Spouse 1 Income

$
$
Schedule C net profit
$
Interest, pensions, etc.
$

Spouse 2 Income

$
$
Schedule C net profit
$
Interest, pensions, etc.
$

State

Marriage Bonus

Marriage Impact
-$150
Saved by filing jointly
Married (MFJ)
$26,815
Total tax
Two Singles
$26,965
Combined tax

Detailed Comparison

ComponentMFJSpouse 1 (Single)Spouse 2 (Single)Penalty (+) / Bonus (−)
Federal Income Tax$15,340$9,870$5,620-$150
Capital Gains Tax$0$0$0$0
Social Security Tax$9,300$5,270$4,030$0
Medicare Tax$2,175$1,233$943$0
Total Credits-$0-$0-$0$0
Net Federal Tax$26,815$16,373$10,593-$150

Effective Tax Rates

Married (MFJ)
Effective Rate17.9%
Marginal Rate29.6%
Spouse 1 (Single)
Effective Rate19.3%
Marginal Rate29.6%
Spouse 2 (Single)
Effective Rate16.3%
Marginal Rate19.7%

How the Marriage Penalty/Bonus Works

A marriage penalty occurs when a married couple pays more in taxes filing jointly than they would as two single individuals. A marriage bonusis the opposite — filing jointly saves money.

The penalty or bonus arises because the MFJ tax brackets, standard deduction, and credit phase-outs are not always exactly double the single amounts. Key sources:

  • Bracket widths:Most 2026 MFJ brackets are exactly 2× the single brackets, but the top brackets (35% and 37%) are narrower, creating a penalty for high-income couples
  • Standard deduction:MFJ standard deduction is exactly 2× single, so no penalty here
  • EITC: MFJ thresholds are only slightly higher than single, creating a penalty for dual-income couples who individually qualify
  • Additional Medicare Tax:The $250,000 MFJ threshold is less than 2× the $200,000 single threshold
  • NIIT:Same issue — $250,000 MFJ vs. $200,000 single
  • State taxes: Many states have their own marriage penalties through non-doubled brackets

When you get a bonus:Couples with very unequal incomes typically benefit from filing jointly, because the lower earner's income fills the bottom tax brackets that the higher earner has already passed through.

When you get a penalty: Equal-income couples with high earnings are most likely to face a penalty, especially above the 35% bracket threshold.