Marriage has significant financial implications for the individuals involved, including its impact on taxation. The calculator below can help estimate the financial impact of filing a joint tax return as a married couple (as opposed to filing separately as singles) based on 2025 federal income tax brackets and data specific to the United States. For tax purposes, whether a person is classified as married is based on the last day of the tax year, which means that a person married on the last day of the tax year is considered married for the entire year. Similarly, a person that is divorced would be considered unmarried for the entire tax year.