As of 2015, individuals must provide their filing status and taxable income in order to use an estimated tax calculator, according to TaxAct. After entering this information, the calculator provides an estimate of income tax owed, tax percentage and tax bracket.
In order to use a federal income tax calculator, individuals must first determine their filing status. Filing statuses include single, married filing jointly, married filing separately and head of household. Individuals must select the status that is applicable to their tax circumstances. Once filing status is selected, individuals must enter their taxable income into the calculator. Individuals determine taxable income by taking their regularly taxed income and subtracting deductions and exemptions. The calculator evaluates this information and provides an estimate of income tax owed, the rate at which taxes are calculated, and the applicable tax bracket, explains TaxAct.
Some tax calculators request additional information in order to provide a more accurate estimate of income tax owed, according to H&R Block. For example, some calculators request more detailed information about income, such as total wages, income tax already withheld, and income other than wages earned. Additionally, some calculators collect information about expenses, such as charitable donations, student-loan interest and child-care expenses to help determine potential deductions.