US Federal vs State Tax — How Both Are Calculated
US Federal vs. State Income Tax: How Both Affect Your Check
When calculating your US take-home pay, your earnings are subject to two primary layers of income taxation: Federal income tax and State income tax. Federal income tax is standard across all fifty states and is administered by the Internal Revenue Service (IRS). State income taxes, however, are governed by individual state departments of revenue, resulting in vastly different tax rates and rules depending on your physical location.
This guide provides a detailed breakdown of how federal and state taxes are calculated, their structural differences, and their impact on your paycheck.
Federal Income Tax: Progressive and Uniform
Federal income tax is calculated on a progressive scale. This means that your income is divided into brackets, and each bracket is taxed at a progressively higher rate.
Calculating Federal Taxable Income
To calculate your federal income tax, you first determine your federal taxable income:
$$\text{Taxable Federal Income} = \text{Gross Earnings} - \text{Pre-Tax Deductions} - \text{Standard Deduction}$$
The Standard Deduction for the 2026 tax year is:
- Single / Married Filing Separately: $16,100
- Married Filing Jointly: $32,200
- Head of Household: $24,150
Once your taxable income is established, it is routed through the IRS progressive tax brackets (10%, 12%, 22%, 24%, 32%, 35%, and 37%) to find your annual tax liability.
State Income Tax: A Patchwork of Rules
Unlike the uniform federal system, state income taxes vary widely. The US is divided into three main state tax structures:
1. States with No Personal Income Tax
There are nine states that levy no personal state income tax on wage income:
- Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming.
Note: In these states, your state income tax deduction is exactly $0.00, allowing you to keep a larger portion of your paycheck.
2. States with a Flat Income Tax
Several states charge a single flat tax rate on all taxable wage income, regardless of how much you earn:
- Colorado: 4.40%
- Illinois: 4.95%
- Indiana: 3.05%
- Michigan: 4.25%
- North Carolina: 4.50%
- Pennsylvania: 3.07%
3. States with Progressive Income Taxes
The majority of US states operate progressive income tax brackets, similar to the federal system. These brackets can be mild or highly progressive:
- California: Operates ten progressive brackets, with rates ranging from 1.00% up to a top marginal rate of 13.30% (for taxable incomes exceeding $1 million).
- New York: Applies progressive rates ranging from 4.00% to 10.90%.
Key Differences in Calculations
| Feature | Federal Income Tax | State Income Tax |
|---|---|---|
| Administration | Internal Revenue Service (IRS) | State Department of Revenue |
| Rates | Uniform across the US (10% to 37%) | Varies by state (0% to 13.3%) |
| Standard Deductions | Standardized ($16,100 for Single) | State-specific deductions or credits |
| Local Taxes | None | Some states allow city/county taxes |
Multi-State Tax Withholding
If you live in one state but work in another, or if you work remotely for an employer in a different state, you may be subject to multi-state tax withholding:
- State of Residence: You are generally required to report all income to your home state.
- State of Work (Physical Location): You typically owe taxes to the state where you physically perform the work.
- Reciprocal Agreements: Many neighboring states (such as Maryland and Virginia, or Illinois and Iowa) have reciprocal agreements. Under these agreements, you only pay income tax to your state of residence, simplifying your paycheck calculations.