How We Calculate
Complete transparency on every data source, formula, and update schedule behind SalaryGiga’s results.
Our Commitment to Accuracy
Every salary calculator on SalaryGiga is built on official U.S. government data. We do not estimate, interpolate between old data, or source numbers from third-party salary databases. If the IRS publishes a new withholding table, we update within 72 hours.
This page documents every data source we use, how we apply it, and how often it is reviewed. If you find an error, contact Sarah directly — she personally reviews every accuracy report.
How We Calculate Federal Withholding
Federal income tax withholding is calculated using the IRS Percentage Method, as published annually in IRS Publication 15-T. We implement both the Worksheet 1 (Withholding from Periodic Payments) and Worksheet 3 (Standard Withholding Rate Schedules) methods.
Taxable Income = Gross Annual Salary − Standard Deduction
# 2024: Single = $14,600 | MFJ = $29,200 | HOH = $21,900
Federal Tax = Sum of marginal rates applied per bracket
# 10%, 12%, 22%, 24%, 32%, 35%, 37%
Effective Rate = Total Federal Tax ÷ Gross Annual Salary × 100
2024 Federal Tax Brackets
| Rate | Single Filers | Married Filing Jointly |
|---|---|---|
| 10% | $0 – $11,600 | $0 – $23,200 |
| 12% | $11,601 – $47,150 | $23,201 – $94,300 |
| 22% | $47,151 – $100,525 | $94,301 – $201,050 |
| 24% | $100,526 – $191,950 | $201,051 – $383,900 |
| 32% | $191,951 – $243,725 | $383,901 – $487,450 |
| 35% | $243,726 – $609,350 | $487,451 – $731,200 |
| 37% | Over $609,350 | Over $731,200 |
Source: IRS Revenue Procedure 2023-34. Brackets are inflation-adjusted annually.
State Tax Rates — All 50 States
State income tax rates are sourced directly from each state’s Department of Revenue or equivalent tax authority. We maintain a database of all 50 state tax schedules, including states with no income tax (Texas, Florida, Washington, Nevada, Wyoming, Alaska, South Dakota), flat-rate states, and progressive bracket states.
Identify state residency
The user’s selected state determines which tax schedule applies. We account for states that tax wages differently from investment income.
Apply state standard deduction
Many states have their own standard deductions or exemptions, which differ from the federal standard deduction. We apply state-specific deductions.
Calculate state marginal tax
Progressive states use tiered brackets. Flat states apply a single rate. Zero-tax states (TX, FL, etc.) apply $0 state withholding.
Account for local taxes
Cities including New York City, Philadelphia, and San Francisco impose local income taxes. These are included where applicable.
Social Security & Medicare Withholding
FICA taxes are applied at fixed rates set by the Social Security Administration and confirmed in IRS Publication 15.
2024 FICA Rates
Source: SSA.gov, IRS Publication 15 (Circular E) 2024.
Internal Revenue Service (IRS)
Publication 15-T contains the Percentage Method and Wage Bracket Method withholding tables. Revenue procedures announce annual inflation adjustments to tax brackets, standard deductions, and contribution limits.
Bureau of Labor Statistics (BLS)
The OEWS program produces employment and wage estimates for over 800 occupations. We use BLS OEWS data to power our “Is My Salary Good?” and “Salary by Occupation” features, showing median, 25th, and 75th percentile wages at national, state, and metro-area levels.
U.S. Census Bureau
The ACS 1-Year and 5-Year estimates provide detailed income and cost-of-living data at the county, metro, and state level. We use ACS data to calculate our Cost of Living Index and to contextualize median income for “Is $X a good salary in [City]?” pages.
HUD Fair Market Rents
HUD publishes Fair Market Rents annually for 530 metropolitan areas. FMRs represent the 40th percentile gross rents for standard-quality rental housing. We use FMR data as the housing component in our cost of living comparisons.
Update Schedule
Sarah reviews all data sources on the following schedule:
“I personally verify every tax rate, bracket, and data source on this site. If you find an error in any of our calculations, I want to know immediately.”