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How the calculator works

Methodology and source register

HourlyPaycheck turns the details you enter into an estimate using documented tax tables and assumptions. This page separates official source data, calculator arithmetic and unsupported details so the result can be checked rather than taken on trust.

Tax tables checked

August 27, 2026

Salary data checked

August 28, 2026

Method reviewed

August 28, 2026

Calculation flow

  1. 1

    Gross pay

    Hourly rate × weekly hours × 52, with overtime added when entered.

  2. 2

    Taxable wages

    Qualifying pre-tax entries are applied according to the tax category selected.

  3. 3

    Deductions

    Federal withholding, Social Security, Medicare and supported state items are calculated.

  4. 4

    Take home

    Modeled deductions and post-tax entries are subtracted, then the annual result is divided by the selected pay frequency.

Weekly, biweekly, semi-monthly and monthly displays use 52, 26, 24 and 12 standard periods. An employer calendar, rounding method or year-to-date threshold can make one real paycheck differ from this annual-average view.

Source register

AreaPrimary sourceUsed for
Federal income taxIRS Revenue Procedure 2025-322026 tax brackets and standard deductions
Federal withholdingIRS Publication 15-T (2026)Payroll-period withholding methods and Form W-4 inputs
Social Security and MedicareIRS Topic 751 and SSA contribution baseEmployee FICA rates, Additional Medicare rules and the wage base
State deductionsState revenue and labor agenciesState withholding methods, certificates and represented employee contributions
Occupation payBLS Occupational Employment and Wage Statistics, May 2025Published employment and wage estimates; tax results are calculated separately

The Social Security wage base is cross-checked against the SSA contribution and benefit base. State pages explain the represented rule and identify important exceptions.

What automated checks cover

  • Selected federal withholding examples and tax-table boundaries.
  • State calculation fixtures, payroll contributions and previously found regressions.
  • Route, canonical, metadata, sitemap and public-data relationships.

A passing test suite is not independent tax or payroll certification. It cannot prove that every source interpretation or input combination is correct.

What is not fully modeled

  • Most city, county, school-district and other local income taxes.
  • Every credit, exemption, benefit, garnishment or employer payroll practice.
  • Prior paychecks, year-to-date withholding and midyear employment changes.
  • Individual tax advice or a guaranteed payroll result.

Publisher and corrections

HourlyPaycheck is published by Onoir Studio Limited. No CPA or payroll specialist review is claimed. If a result or source appears wrong, send the page address, inputs, expected result and supporting source to hello@hourlypaycheck.com.