Irs Interest Rates 2024 Calculator. This decision affects how much interest is calculated on both overpayments and underpayments of taxes. When you are looking at the federal tax brackets, you are able to determine which tax rate applies to you for the current tax season which allows you to go on and determine how much tax you will be paying based on your income.

Each month the irs publishes a set of interest rates. Irs interest rates increased continually beginning on april 1, 2022.