How one paycheck is taxed
A paycheck cannot be taxed on its own, because federal income tax is progressive and assessed across a whole year. Payroll therefore annualises: it multiplies your gross for the period by the number of periods in the year, works out the federal position on that figure, then divides the result back down. CalcSenses does exactly the same thing, which is why the pay frequency you choose changes the answer.
weekly 52 · biweekly 26 · semi-monthly 24 · monthly 12Biweekly and semi-monthly are easy to confuse. Biweekly means every two weeks, which is 26 paychecks a year. Semi-monthly means twice a month, which is 24. Two people on the same salary will see different per-paycheck figures depending on which one their employer uses.
Withholding is not the same as liability
Your employer follows withholding rules; your tax return settles the actual liability. The clearest example is Additional Medicare Tax. An employer must withhold 0.9% on wages above $200,000 without regard to filing status. But a married couple filing jointly does not actually owe it until combined wages pass $250,000. That gap is reconciled on the return, not in payroll — and this calculator uses the withholding rule, because that is what shows up on a payslip.
Worked example · $2,500 biweekly, single filer
- $2,500 × 26 paychecks = $65,000 of annual gross pay.
- Subtract the $16,100 standard deduction for $48,900 of taxable income.
- Apply the 2026 brackets progressively, then add Social Security and Medicare on the full gross.
- Divide the annual net back by 26 to get the estimated net paycheck.
Reading your payslip against this estimate
Compare line by line rather than on the bottom figure alone. Federal withholding is the line most likely to differ, because your Form W-4 can add dependents, other income, deductions or an extra fixed amount that this calculator does not ask for. Social Security and Medicare should match closely, since they are simple percentages of gross wages.
Paycheck calculators by state
In nine states the state-tax line on a paycheck is a verified zero, and each has a dedicated page explaining how that state actually works: Texas, Florida, Washington, Nevada, Tennessee, New Hampshire, Alaska, South Dakota and Wyoming. States that do tax wages stay in the selector but out of the result until their schedules are transcribed.
What’s included, and what isn’t
Every figure this calculator produces is an estimate. Here is exactly what it accounts for, and what it does not.
What’s included
- Federal income tax, using the published brackets and standard deduction for your filing status.
- Employee Social Security at 6.2%, capped at the annual wage base.
- Employee Medicare at 1.45%, plus Additional Medicare Tax where it applies.
- Any pre-tax contributions you enter, applied to federal taxable income only.
- State income tax for the nine states that levy none on wages — a verified zero, not an omission.
- Conversion between your pay period and the annual figures payroll works from.
What’s not included
- State income tax outside the states listed as levying none on wages.
- County, city and other local income taxes.
- Tax credits, itemised deductions and above-the-line adjustments.
- Employer benefits, insurance premiums and post-tax deductions.
- Form W-4 adjustments such as dependants, other income or extra withholding.
- Bonuses, commission and overtime, which payroll often withholds at a separate supplemental rate.
- Multiple jobs, a working spouse's income, and mid-year pay changes.
What this calculator assumes
- Uses the federal standard deduction for the selected filing status and tax year.
- Assumes W-2 employment at one job for the full calendar year.
- Pre-tax contributions reduce federal taxable income but not Social Security or Medicare wages.
- Social Security stops at the $184,500 wage base for 2026.
- Additional Medicare Tax follows the employer withholding rule: a flat $200,000 of wages, regardless of filing status.
- Assumes every paycheck in the year is the same size, which is what makes an annualised estimate meaningful.
- Models what an employer withholds, not your final tax return. The two can differ.
Sources
Every rate and threshold above is transcribed from a primary source and re-checked on the date shown.
Frequently asked questions
How is this different from the salary calculator?
This one models what your employer withholds from a single paycheck; the salary calculator models what you owe for the whole year. The difference matters most for Additional Medicare Tax: employers withhold it on wages above a flat $200,000 regardless of filing status, while your actual liability threshold depends on how you file.
Why does the calculator annualise my paycheck?
Federal income tax is progressive and assessed on a full year of income, so a single paycheck cannot be taxed in isolation. The calculator multiplies your gross by the number of pay periods in the year, works out the annual position, then divides back down. That is the same approach payroll systems use.
My paychecks are not all the same size. Is this still useful?
It is still a good estimate for a typical period, but overtime, bonuses and commission make real withholding vary. Supplemental wages such as bonuses are often withheld at a different flat rate, which this calculator does not model.
Does it include state and local withholding?
Only for states that levy no income tax on wages, where zero is the correct answer. Other states are listed but excluded until their 2026 withholding schedules are transcribed. County and city taxes are never included.
Why is my real paycheck smaller than this estimate?
Health and dental premiums, life insurance, union dues, garnishments, HSA and FSA contributions, post-tax Roth deferrals and employer-specific deductions all come off a real payslip. This calculator covers taxes and the pre-tax amount you enter, nothing else.