Federal vs. state vs. local
Federal income tax uses progressive marginal brackets — only the income inside each bracket is taxed at that bracket's rate. State income tax follows the same idea in 32 states; nine states use a single flat rate, and nine have no wage income tax at all. Sales tax is a state-and-local affair: 45 states plus D.C. impose a base rate, and most allow counties or cities to add their own. The Income Tax Calculator handles the federal-plus-state stack; Sales Tax Calculator covers the state-plus-local side.
Capital gains and self-employment
Investment profits and freelance income each have their own rules. The Capital Gains Tax Calculator handles short- and long-term gains, including the 3.8% Net Investment Income Tax (NIIT) for higher earners. The Self-Employment Tax Calculator models Schedule SE — the 15.3% combined Social Security and Medicare tax that 1099 contractors and small-business owners owe on net earnings, plus the deductible employer-equivalent half and quarterly estimated payments.
What changed in 2026
The One Big Beautiful Bill Act updated federal brackets, the standard deduction, and several credits for the 2026 tax year. All calculators on this hub reflect the current rules. For a full overview of what changed and which calculators are year-keyed, see 2026 Tax Calculators.
Per-state coverage
Each of the 51 income-tax pages listed above includes that state's brackets, standard deduction, personal exemptions, and any local taxes that affect the math (NYC, Philadelphia, Detroit, etc.). The sales-tax pages cover state base rate plus typical local rates and link out to each state's Department of Revenue address-lookup tool when one exists.
Related categories
Paycheck withholding — what's taken out per paycheck rather than what you owe for the year — lives in Payroll Calculators. Tax-advantaged long-term saving (401(k), IRA, retirement) is under Savings & Investing.