Marriage penalty or marriage bonus?
Married couples usually file one joint return. Whether that raises or lowers their federal income tax depends mostly on how their incomes compare:
- Marriage bonus – common when one spouse earns much more than the other. The joint brackets let the higher income spill into lower brackets.
- Marriage penalty – can happen when both spouses have high and similar incomes, because the top joint brackets are less than double the single brackets.
For most couples with two similar middle incomes, nothing changes: the 2026 standard deduction ($32,200 joint vs. $16,100 single) and the brackets up to 24% are exactly double the single amounts.
The calculator compares two single returns (the higher earner files as head of household if there are children) with one joint return, using 2026 brackets, the standard deduction and the child tax credit.
Frequently asked questions
Should we file separately to avoid a penalty?
Rarely. Married filing separately usually costs more and blocks credits such as the earned income credit and education credits. Compare both ways before you file.
Are there other marriage penalties?
Yes. Some credits and deductions, like the earned income credit and the state and local tax (SALT) deduction cap, are not doubled for couples. State taxes can differ too.
Does the date of the wedding matter?
Your marital status on December 31 decides your filing status for the whole year.