Federal Income Tax Calculator: Estimate Your 2026 Tax Bill

From gross income to the tax line

Federal income tax is a chain of subtractions followed by marginal rates, not one rate on your whole income. Start with gross income. Pre-tax items such as 401(k) contributions and HSA deposits come off first, producing adjusted gross income. The standard deduction for your filing status, or your itemized total if it is larger, comes off next and leaves taxable income. The brackets then tax that amount in slices, each slice at its own rate, and credits are subtracted at the very end, dollar for dollar. The table under the calculator prints each step.

A single filer at $85,000, step by step

Take a single filer earning $85,000 who puts $5,000 into a 401(k). Adjusted gross income is $80,000. The $16,100 standard deduction brings taxable income to $63,900. Running the brackets produces about $8,770 of federal income tax, an effective rate of 10.3%, even though the top slice of that income sits in the 22% bracket. That gap is the whole point of marginal taxation: only the income above each threshold pays the higher rate.

Standard or itemized, in plain words

The standard deduction is a flat amount every filer may subtract, no receipts required. Itemizing means adding up specific expenses instead: mortgage interest, state and local taxes, charitable gifts, and medical costs above a threshold. You get one or the other, never both, so itemizing only helps when the list beats the flat amount. The calculator applies whichever is larger.

Credits and deductions pull different levers

A deduction shrinks the income that gets taxed, so it is worth your marginal rate times the amount: a $1,000 deduction in the 22% bracket saves about $220. A credit shrinks the tax itself, one for one. The child tax credit is worth up to $2,200 per qualifying child, so a married couple at $85,000 with two children sees tax before credits of $5,840 fall to about $1,440. Part of it is refundable even after the bill reaches zero.

Your bracket is not your rate

People say they are "in the 22% bracket" as if that rate applied to everything, and overestimate what a raise will cost. Marginal rate is the tax on the next dollar; effective rate is total tax divided by total income, and it is always lower because the lower slices keep their lower rates. Our guide to marginal versus effective rates works the arithmetic and shows why a raise never leaves you with less after tax.

When to run this estimate

Run it when your W-4 needs a check, after a raise, a marriage, or a new child, before deciding whether to itemize, and when weighing how much to send to a 401(k). It covers federal income tax only; for what a paycheck actually delivers after Social Security, Medicare, and state tax, the paycheck calculator picks up where this one stops.