Reference Articles

Tax Rule Reference Library

These articles explain the core federal tax concepts that compensation and salary calculators rely on. Each article covers how a rule works, why it matters, and where to go to estimate your own situation.

Income Tax

Federal Income Tax Brackets

How the progressive bracket system works, and why a higher income does not mean your entire income is taxed at the top rate.

Read article → Deductions

The Standard Deduction Explained

How the standard deduction reduces taxable income, what the amounts are by filing status, and how it interacts with salary estimates.

Read article → Self-Employment

Self-Employment Tax Rules

Why contractors and freelancers owe both the employee and employer portions of Social Security and Medicare, and how that affects take-home pay.

Read article → Supplemental Wages

How Bonus Income Is Taxed

The IRS treats bonus payments as supplemental wages, which affects how withholding is calculated — often differently from a regular paycheck.

Read article → Estimated Payments

Estimated Quarterly Tax Rules

Who may be required to make quarterly estimated tax payments, how the payment schedule works, and what underpayment means in general terms.

Read article →
Using This Site

How to Use This Reference

Start with a concept

If you are using a tax or salary calculator and want to understand what rule is behind a number, find the relevant article in the library above. Each article explains a specific federal rule or concept in plain language.

Then run an estimate

Once you understand how a rule works conceptually, the related calculator tools below let you apply numbers to your own situation. Calculators estimate outputs — always verify anything consequential with official IRS materials or a tax professional.

Rules can change

Federal tax law is updated regularly. Congress adjusts brackets for inflation, changes standard deduction amounts, and periodically revises rates. The articles here explain how rules generally work, not a guaranteed current figure.

No advice provided

Nothing on this site is tax, legal, or financial advice. The content here is for general informational purposes. Your individual circumstances may produce different results than any general rule suggests.

Important Notice

Calculators Estimate — Verify What Matters

Estimates are not guarantees. Online calculators, including the tools linked from this site, produce estimates based on simplified rules and general assumptions. They do not account for every deduction, credit, withholding situation, or state-level rule. For anything important — filing decisions, estimated payment amounts, employment agreements — consult the IRS directly or work with a qualified tax professional.

Official IRS resources can be found at irs.gov. Publication 505 covers tax withholding and estimated tax. Publication 15 covers employer withholding rules. These are the authoritative sources for how federal tax rules actually apply.

Supported Tool Categories

What These Articles Support

This reference site was built to support a cluster of compensation and tax estimation calculators. The articles here explain the underlying rules those tools use. Below are the categories of calculators this reference supports:

  • Salary take-home calculators — tools that estimate net pay after federal income tax, FICA, and standard deductions
  • 1099 vs W-2 comparison calculators — tools that compare contractor and employee compensation after accounting for self-employment tax and deductibility
  • Quarterly estimated tax calculators — tools that estimate what an individual may owe in quarterly federal tax payments
  • Bonus withholding calculators — tools that estimate federal withholding on supplemental wages and bonus payments
  • Total compensation calculators — tools that aggregate base salary, benefits, and equity into a comparable total value
Common Questions

Frequently Asked Questions

  • Does this site give tax advice?
    No. This site provides general informational explanations of how federal tax rules work. It does not provide advice tailored to any individual's tax situation.
  • Are the numbers on this site current?
    Tax amounts and bracket thresholds change periodically. This site explains how rules work conceptually. Always verify specific figures with the IRS or a current professional source.
  • Why might calculator results differ from my actual withholding?
    Calculators use simplified assumptions. Real withholding depends on your W-4 elections, employer practices, additional income sources, state taxes, and other individual factors.

View all FAQs →