The formula
How it works
See whether marrying costs or saves you tax. Enter each person’s income and the calculator compares filing as two singles against filing jointly, revealing a marriage penalty or a marriage bonus.
FAQ
What causes a marriage penalty or bonus?
When two similar incomes combine, they can be pushed into higher brackets together, creating a penalty. When one earns much more than the other, joint filing spreads income across lower brackets, creating a bonus. The bigger the gap between the two incomes, the more likely a bonus.
Is this a full tax calculation?
It is a federal-only estimate using the 2024 brackets and standard deductions. It ignores credits, state taxes and other filing statuses, so the exact penalty or bonus on a real return may differ. It is meant to show the direction and rough size of the marriage effect.
Why do the standard deductions differ between single and joint filing?
The joint standard deduction is exactly double the single one, but the tax brackets above the lowest rates are not simply doubled, which is where a penalty for two similar high earners can creep in.
Can a couple with very different incomes get a bigger bonus?
Yes — when one partner earns much more than the other, combining incomes lets more of the higher earner’s income be taxed at the lower rates that apply to the lower earner, producing a larger bonus.
Does this calculator include children or other dependents?
No — it compares only the two incomes against the single and joint brackets and standard deductions, without credits like the Child Tax Credit that can also shift the outcome.
Can married couples choose to file separately instead?
Yes, "married filing separately" is an option, but it usually results in a higher combined tax than filing jointly, so it is rarely used purely to avoid a marriage penalty.
Does the marriage penalty apply to every couple?
No — many couples, especially those with one dominant income, see a bonus rather than a penalty; the penalty mainly shows up when two earners have similar, higher incomes.
About the marriage tax calculator
This calculator shows the “marriage penalty” or “marriage bonus” — the change in federal income tax that comes from filing jointly as a married couple instead of as two single people. It computes each person’s tax as a single filer, adds them, and compares that with the couple’s tax filing jointly. The difference tells you whether the tax code rewards or penalises your marriage.
How to use it
Enter each partner’s annual income. The calculator shows the combined tax if you both filed as singles, the tax if you file jointly, and the difference. A positive difference is a penalty (you pay more married); a negative one is a bonus (you pay less). For example, two equal high earners often face a small penalty, while a single-earner couple usually gets a bonus.
The formula
The marriage effect is , where each single tax applies the single brackets and standard deduction, and the joint tax applies the married-filing-jointly brackets and deduction. Because the joint brackets are not simply double the single ones at the top, equal incomes can be pushed higher together, which is where penalties arise.
Where it is used
Couples use it when planning a wedding or a joint financial year to anticipate the tax impact, and to understand why two paychecks can be taxed differently once combined. Financial planners use it to advise on filing choices. While the effect is usually modest, it can be meaningful for couples with either very similar or very different incomes, and it is worth checking before assuming marriage is tax-neutral.