Editorial Policy & Methodology
How we source, write, and maintain every piece of content on FiscalStrong.
Content Sourcing
All tax rate data is sourced from the following primary authorities:
- IRS publications, federal tax brackets, standard deductions, FICA rates, contribution limits, and IRA/401(k) rules.
- Federation of Tax Administrators (FTA), state individual income tax rates.
- Tax Foundation, state and local sales tax rates, property tax rates, and total tax burden rankings.
- Each state's Department of Revenue, official state tax forms, instructions, filing deadlines, and recent law changes.
- U.S. Congress, SECURE Act 2.0, TCJA, and other federal tax legislation via congress.gov.
Review Process
Every article passes through the following review pipeline:
- Research, Sources verified against primary IRS publications, federal tax code, and official state revenue department materials.
- Writing, Content drafted by our editorial team with focus on accuracy and clarity for general readers.
- Source verification, Every factual claim is checked against the cited primary source.
- Publication, Published with publication date, last-reviewed date, and full source list visible.
- Annual re-review, All content is re-reviewed at least annually, and immediately following major tax law changes.
Calculator Methodology
Our calculators use the following assumptions:
- Income Tax Calculator: 2025 federal brackets, 2025 standard deduction, 2025 FICA rates ($176,100 SS wage base). State tax uses detailed slab-wise brackets for progressive states where available, flat rate for flat-tax states, and a blended estimate for others.
- Mortgage Calculator: Standard amortization formula. Property tax based on home value (not loan amount). PMI not included automatically.
- Retirement Calculator: Monthly compounding. 4% safe withdrawal rate for retirement income projection.
- Compound Interest Calculator: User-selected compounding frequency. Year-by-year projection based on periodic rate.
- Roth vs Traditional IRA: Assumes same pre-tax dollars available for both options. Roth contribution reduced by current tax rate.
- Auto Loan Calculator: Standard amortization. Sales tax applied to purchase price (varies by state, verify your state's rules).
- Credit Card Payoff Calculator: Uses daily-period-rate method matching most U.S. credit card issuers.
- Net Worth Calculator: Simple sum of assets minus liabilities. No tax implications modeled.
- Capital Gains Tax Calculator: Uses 2025 federal long-term brackets (0/15/20%) plus 3.8% NIIT for high earners. State capital gains not included.
All calculators are planning tools only. They do not account for credits (EITC, child tax credit, education credits), additional taxes (AMT, NIIT), itemized deductions, or state-specific adjustments. For your exact tax liability, consult a qualified licensed professional.
State Tax Data Methodology
Our state tax data comes from official government sources and recognized research organizations. Here is exactly how each figure is sourced and what it means:
Income Tax Rates (Top Marginal)
The top marginal individual income tax rate from each state's Department of Revenue or taxation authority. For progressive states, this is the rate applied to income in the highest bracket only, not the effective rate on all income. For flat-tax states, this is the single rate applied to all taxable income. Source: Each state's official Department of Revenue website (linked on every state page).
Income Tax Brackets (Slab-Wise)
For progressive states, we provide detailed single-filer bracket tables showing the rate and income range for each slab. These are from each state's official tax forms and instructions for the 2025 tax year. Married filing jointly brackets are typically double the single amounts but vary by state, always consult official sources.
State Sales Tax (Base Rate)
The official state-level sales tax rate set by state law. This is the rate that applies statewide before any local additions. Source: Each state's Department of Revenue. For example, California's state rate is 7.25% (which includes a mandatory 1% uniform local rate), Texas is 6.25%, and New York is 4.0%.
Average Local Sales Tax
The weighted average of all local sales tax rates (city, county, and special district) across the state, weighted by population or economic activity. This is NOT the rate you actually pay unless you live in a jurisdiction with exactly this rate. Your actual local sales tax may be higher or lower. Source: Tax Foundation "State and Local Sales Tax Rates" report, which calculates these averages from state DOR data and the Census of Governments.
Combined Sales Tax (State Average)
State base rate plus average local add-on. This is a state-wide average for comparison purposes only. The actual combined rate at any specific address depends on the local jurisdictions that apply. For example, in Alabama the state average is 9.29%, but actual combined rates range from 4% (state only in some unincorporated areas) to over 11% (in cities with high local rates).
Average Effective Property Tax Rate
Total property tax collected in the state divided by total market value of owner-occupied housing. This is an "effective" rate, meaning it reflects actual taxes paid as a percentage of actual home values, not the nominal millage rate. Property tax rates vary significantly within each state by county, city, school district, and special district. Source: Tax Foundation analysis of U.S. Census Bureau data.
Median Property Tax Bill
The median annual property tax paid on owner-occupied housing units in the state. Half of homeowners pay less, half pay more. This reflects actual tax bills, not rates, so it captures the combined effect of tax rates and home values. Source: U.S. Census Bureau American Community Survey (ACS) 5-year estimates.
Important: Sales tax and property tax rates vary by location within each state. The figures on this site are state-wide averages for comparison purposes. Always verify your actual local rates with your state's Department of Revenue (for sales tax) and your county tax assessor (for property tax) before making financial decisions.
Conflicts of Interest
FiscalStrong is an educational publisher. We do not sell financial products, earn commissions on recommendations, or accept payment for editorial coverage. We may display advertising (including Google AdSense) on the site; advertising never influences editorial content. All advertising is clearly distinguished from editorial content.
Corrections Policy
If you find an error in our content, please contact us. We investigate all reported errors within 5 business days and publish corrections with a dated changelog at the bottom of the affected article.
Update Frequency
State tax data is reviewed annually in January following each state's legislative session. Federal tax data is updated immediately after IRS releases annual inflation adjustments (typically October-November). Articles are re-reviewed on their last-reviewed date (visible on each article).