Free federal income tax refund calculators are available online at from general websites such as CalcXML and from tax preparation sites such as Taxbrain. Unlike other sites, these two offer income tax refund calculators without requiring the user to log in or provide contact information before receiving calculation results.
Tax refund calculators use data such as income, number of dependents, tax credit eligibility and amount of withholding to estimate a refund amount, according to the information required for input into the TaxBrain calculator.
While many taxpayers anticipate a large refund, a wiser course is to avoid the overpayment of tax that results in refunds, advises Investopedia. The IRS provides an online calculator that allows taxpayers to determine proper withholding amounts.