Marriage Tax Calculator

The marriage tax penalty occurs when two people pay more in federal income taxes filing as married filing jointly than they would have paid combined as single filers. This typically happens when both spouses have similar incomes, because the married filing jointly tax brackets are not always exactly double the single brackets at higher income levels, pushing the couple into a higher marginal rate.

A marriage bonus occurs when a couple pays less tax filing jointly than they would have paid as two single filers. This most commonly happens when there is a large income disparity between the spouses. The higher-earning spouse's income is effectively shifted into lower brackets by the more favorable married filing jointly bracket thresholds, reducing the overall tax bill.

Married filing separately (MFS) is rarely beneficial for avoiding the marriage penalty. MFS filers lose access to many deductions and credits — including the earned income credit, the student loan interest deduction, and education credits — and the MFS tax brackets are the same as the single brackets, not more favorable. In most situations, married filing jointly results in a lower combined tax than filing separately.

The standard deduction for married filing jointly is exactly double the single standard deduction ($30,000 vs $15,000 for 2025), so the deduction itself is neutral. The penalty or bonus arises from how the tax brackets are structured. Couples who itemize may also find that combining income affects phase-outs for mortgage interest, state and local taxes (SALT), and other deductions, which can amplify or reduce the marriage penalty depending on their circumstances.