Where can you find a federal income tax calculator online?

The IRS, H&R Block and TurboTax offer income tax calculators on their websites. The IRS calculator provides an estimate of income tax for the upcoming year, while the others determine income tax based on W-2 information from the previous tax year.

IRS calculator users need a recent pay stub and their most recent tax return. Users enter information about dependents, deductions and expenses to determine tax withholding for the coming year. The results help them make any necessary adjustments to Form W-4. TurboTax and H&R Block tax calculators use W-2 information, such as wages, itemized deductions and taxes withheld, to determine the tax refund or taxes owed for a previous year.