2026 Income Tax Calculator: Federal Bracket Estimator

A US federal income tax bill is built in layers, not applied as one rate. Gross income is first reduced by the standard deduction, 14,600 dollars for a single filer in tax year 2024, 29,200 for married filing jointly, and 21,900 for head of household, and the remainder is sliced across seven brackets running 10, 12, 22, 24, 32, 35, and 37 percent. Only the slice of income inside each band is taxed at that band's rate, which is why the marginal rate on the last dollar earned is always higher than the effective rate on the whole. A single filer at 75,000 dollars gross sits in the 22 percent bracket but pays an effective federal rate closer to 11 percent. Payroll tax follows a different logic and is layered on top. Social Security is 6.2 percent of wages up to the 2024 wage base of 168,600 dollars and stops entirely above it, making it regressive at high incomes, while Medicare is 1.45 percent on every dollar with an extra 0.9 percent surtax above 200,000 single or 250,000 joint. Employers match the base amounts, so the true wedge is 15.3 percent. State tax is modelled here as a single flat rate per state, which is a simplification: most states use their own brackets, deductions, and credits, nine levy no wage income tax at all, and local city taxes are not captured.

Congress first taxed income in 1861 to fund the Civil War, and the Revenue Act of 1862 created the office that became the Internal Revenue Service. That tax lapsed in 1872, and when a later version was enacted the Supreme Court struck it down in Pollock v. Farmers Loan and Trust Company in 1895 as an unapportioned direct tax. The remedy was constitutional: the Sixteenth Amendment was ratified in February 1913, and the Revenue Act of October 1913 imposed a 1 percent normal rate with surtaxes reaching 7 percent on income above 500,000 dollars. Fewer than 1 percent of households owed anything. Two wartime changes made the modern system. Rates and coverage expanded enormously during the Second World War, turning a class tax into a mass tax, and the Current Tax Payment Act of 1943 introduced payroll withholding so that tax was collected as income was earned rather than in a lump sum the following year. The payroll levies arrived separately: the Social Security Act of 1935 began collecting contributions in 1937 at 1 percent from employee and employer each, and Medicare was added in 1965. Bracket counts have swung widely since, from more than 20 in the 1970s down to two after the Tax Reform Act of 1986, and the current seven-bracket structure with its enlarged standard deduction dates from the Tax Cuts and Jobs Act of 2017.