# Paycheck calculation method and tax sources

Source: https://payinview.com/us/paycheck-methodology

Understand the 2026 federal withholding method, dated state tax baseline, payroll-entry option, deductions, source dates, and paycheck estimate limits.

Use the [paycheck calculator](https://payinview.com/us/paycheck-calculator) to estimate take-home pay with the methods below.

## Two different tax methods, clearly separated.

The paycheck tool is a budgeting tool for one W-2 job, one state of residence and work, and single or married-filing-jointly status. It is not a tax return, payroll service, or a determination of all deductions due. It does not support head of household, married filing separately, nonresident-alien adjustments, cross-state work, or self-employment.

## Federal income-tax withholding: 2026 IRS method

We use [IRS Publication 15-T (2026), Worksheet 1A and the annual percentage schedules](https://www.irs.gov/publications/p15t) for a 2020-or-later W-4. Taxable pay is annualized using 52, 26, 24, or 12 periods. The calculation applies filing status, the Step 2(c) checkbox, annual Step 3 credits, annual Step 4(a) income, annual Step 4(b) deductions, and per-check Step 4(c) extra withholding. Credits cannot reduce withholding below zero. An entered exemption removes federal income-tax withholding, not FICA.

The standard schedules are equivalent to applying the 2026 federal brackets after the $16,100 single / $32,200 joint standard deduction. Step 2(c) uses the corresponding half-width schedules. Amounts round to cents per withholding component. Supplemental-wage flat-rate withholding and pre-2020 W-4 forms are not modeled.

## Social Security and Medicare: current-check calculations

Employee Social Security is 6.2%, limited to $184,500 of wages in 2026. Medicare is 1.45%, with no wage cap. Employers withhold another 0.9% of wages paid above $200,000 in the calendar year, regardless of filing status. Enter previous FICA-taxable wages from the same employer, before this paycheck. This model assumes Social Security and Medicare have the same uncapped taxable wage basis. Use a different calculation if your employment has special FICA treatment. Source: [IRS Topic 751](https://www.irs.gov/taxtopics/tc751) and [SSA annual wage bases](https://www.ssa.gov/oact/cola/cbb.html).

## State income tax: a dated bracket planning baseline

The state data comes from [Tax Foundation’s 2026 state individual income-tax compilation](https://taxfoundation.org/data/all/state/state-income-tax-rates-2026/), a secondary source with data as of 2026-02-11. We checked the publication on 2026-10-23. A retrieval date does not make every table entry current. The source includes prior-year values where 2026 adjustments were not available and some scheduled changes. These are annual income-tax brackets, not state payroll withholding schedules.

The basic state model annualizes wages less your entered state pre-tax deductions, applies the listed standard deduction, personal exemption, brackets, and personal credit, then divides by pay periods. It includes Alabama’s standard-deduction decrease and federal-tax deduction; Connecticut’s personal-exemption decrease; Illinois’s exemption cutoff; Ohio’s income-based exemption and $332 bracket base; Utah’s baseline credit decrease; Wisconsin’s linear standard-deduction phaseout; California’s 1% million-dollar surcharge; and Vermont’s 3% minimum comparison.

It omits dependent benefits, many state credits and subtractions, tax-benefit recapture, and several high-income phaseouts. State-specific notes show additional limits. It is not a full annual state return. Arkansas’s separate lower-income tables and South Carolina’s scheduled midyear change make those automatic baselines unsuitable, so a payroll state-tax entry is required. Other states with carried-forward values are marked in their page notes. Do not use this baseline as a claim that your employer withheld the wrong amount.

Select  **Enter payroll amount**  for a closer current-check estimate. This replaces the state bracket estimate with your entered income-tax amount. Amounts are kept separately for each state, so changing state cannot reuse another state’s withholding. The extra-pay comparison requires an additional state-tax amount when this method is selected.

## Benefits, local taxes, and insurance

Qualifying pre-tax health benefits reduce both federal income-tax and FICA wages in this model. Traditional 401(k)/403(b) contributions reduce federal income-tax wages only. Roth and other after-tax deductions do not reduce taxable wages. State pre-tax deductions are entered separately because state treatment can differ.

Local city, county, school-district, and wage taxes are not calculated automatically. Neither are employee state disability, unemployment, paid-leave, transit, or long-term-care contributions. Enter those amounts from payroll. A zero field means that deduction is not included, not that your state or city has no such deduction. Employer-only taxes must not be entered as employee deductions.

## Gross pay and overtime comparisons

Salary divides equally by the selected number of checks. Gross-pay entry uses your actual entered wages. Hourly entry uses the existing standard federal weekly method, one rate and complete workweeks, after an explicit confirmation. Hours above 40 receive 1.5× pay, and two weeks are never averaged. Monthly and twice-monthly hourly work require gross-pay entry because workweek boundaries differ from those pay periods.

The extra-pay comparison adds your entered gross earnings to this check and recomputes federal withholding, FICA, and the selected state method. It assumes regular-paycheck withholding. Health, retirement, local-tax, insurance, and after-tax deduction amounts stay fixed; increases in those amounts reduce the actual gain. The annualized withholding difference is not a year-end marginal tax forecast.

“No tax on overtime” does not automatically remove all overtime earnings from every payroll tax. Enter the deduction amount from an updated W-4 where applicable. See [Publication 15-T’s qualified overtime section](https://www.irs.gov/publications/p15t). This tool does not determine eligibility or compute that annual deduction.

## Privacy and source checks

Paycheck and W-4 inputs stay in tab memory. They are not sent to a tax API, stored automatically, included in URLs, or added to the existing gross-pay saved-history format. Source text checked 2026-10-23; state baseline date 2026-02-11. The original [gross overtime method](https://payinview.com/methodology) remains separate.