Enter both spouses' taxable incomes to compare combined tax as two single filers against married filing jointly, using 2024 US federal brackets.
The marriage penalty is when a couple pays more combined federal income tax filing jointly than they would have paid as two separate single filers on the same total income. The marriage bonus is the opposite — paying less jointly than the sum of what two single filers would owe. Both effects come purely from how the width of each tax bracket compares between the single and married filing jointly schedules — they aren't separate tax rules, just an artifact of the brackets.
A marriage bonus is common when one spouse earns significantly more than the other, because combining incomes lets the lower earner's income effectively "fill up" the wider joint tax brackets at lower rates instead of the higher earner's income being taxed at their own higher single-filer rate on every dollar. A marriage penalty tends to appear when both spouses earn similar, high incomes, since their combined income can push into the top bracket faster as a couple than it would filing as two separate single people, because not every married bracket threshold is exactly double the single bracket threshold at the highest income levels.
No — this calculator applies only 2024 US federal income tax brackets to the incomes entered. State income taxes have entirely separate brackets, rates, and marriage-filing rules that vary widely from state to state (and some states have no income tax at all), none of which are included here.
No — this calculator applies the tax brackets directly to the incomes you enter and does not subtract the standard deduction, itemized deductions, or any tax credits, so it will overstate the actual dollar tax owed in both the single and joint scenarios. It's designed to isolate and compare the bracket-structure effect specifically — for an actual expected tax bill, use the Tax Calculator, which does apply standard deductions.
Worked example: Spouse A earning $60,000 and Spouse B earning $40,000: combined tax as two single filers is about $12,821.00, versus $12,106.00 filing jointly on the combined $100,000 — a marriage bonus of about $715.00. A more lopsided example, $90,000 and $10,000, produces a larger bonus of roughly $3,747.00, since more of the joint income shifts into wider low-rate brackets. By contrast, two equal high earners at $450,000 each end up with a marriage penalty of about $3,376.00, since their combined $900,000 pushes further into the top 37% bracket jointly than it would as two separate $450,000 single filers.