How This Federal Income Tax Calculator Works
The U.S. taxes income with marginal brackets: the rate climbs as income climbs, but each rate applies only to the dollars inside its bracket. This calculator reproduces that system exactly. First it computes your taxable income — gross income minus pre-tax deductions (like 401(k) and HSA contributions) minus the standard deduction for your filing status. Then it walks that taxable income through the seven brackets, from 10% up to 37%, taxing each slice at its own rate and adding up the pieces.
The formula looks like this:
tax = Σ (ratebracket × income in that bracket)
Example:
taxable income = gross − pre-tax deductions − standard deduction, then each bracket's rate is applied only to the income falling inside it.
Worked example (2026, single filer): $95,000 gross income, $8,000 of pre-tax 401(k) contributions, and the $16,100 standard deduction leave $70,900 of taxable income. The 2026 single brackets tax the first $12,400 at 10% ($1,240), the next $38,000 at 12% ($4,560), and the remaining $20,500 at 22% ($4,510) — for a total of $10,310. The marginal rate is 22% (the bracket the last dollar falls in), but the effective rate — total tax ÷ gross income — is only about 10.9%. That gap is the whole point of marginal taxation, and it's why "I'm in the 22% bracket" never means you pay 22% of everything.
The 2026 figures used here — brackets from 10% to 37% and standard deductions of $16,100 (single), $32,200 (joint), and $24,150 (head of household) — come from IRS Revenue Procedure 2025-32. The IRS adjusts these numbers for inflation every year, which is why the code keeps them in one clearly-labeled block that's easy to refresh each January.
Practical tips
Your marginal rate is the tax on your next dollar, so it tells you the true value of a deduction, a raise, or extra freelance income. A $1,000 deduction saves a 22%-bracket filer $220 but only $120 for a 12%-bracket filer.
Every dollar into a traditional 401(k) or HSA skips income tax this year at your marginal rate. Enter your contributions above to see the immediate tax savings.
Crossing into the next bracket taxes only the dollars above the line at the higher rate. A raise can never make your take-home pay go down on its own.
This estimates what you owe; your employer withholds an approximation. If you consistently get big refunds, you're giving the IRS an interest-free loan — adjust your W-4 instead.
State income tax, FICA payroll tax, and local taxes are separate. For the full paycheck picture, use the Paycheck Calculator.