A free tax calculator estimates the amount of tax a person must pay the Internal Revenue Service or is due back as a refund. As of 2015, TurboTax offers a free tax estimator called TaxCaster, which is available online or as a mobile application, notes the official website.
The IRS has many free calculators for taxpayers to use, notes About.com. These calculators consist of AMT Assistant, Earned Income Credit Assistant and the IRS Withholding Calculator. The tools are efficient, all serving different purposes in the tax filing process. Taxpayers can also use the Paycheck Calculator to ensure their net pay and tax withholding is accurate.