Calculator methodology and data sources
ToolsDoc publishes browser-based planning calculators and explanatory guides. The publisher is ToolsDoc; these pages do not claim an independent audit or professional tax review.
Reference data and tax year
The tax reference dataset is labeled 2026, with a recorded revision date of . This date describes the stored dataset, not a guarantee that every rate remains current. State and local changes can occur after an update.
The federal dataset records IRS Revenue Procedure 2025-32 and the Social Security Administration's contribution base as its references. State datasets record Tax Foundation tables and selected state revenue department updates. To verify a figure for filing, consult the issuing authority:
- IRS Revenue Procedure 2025-32
- Social Security contribution and benefit base
- IRS directory of state government and tax websites
State income tax estimates
The state calculators start with annual wages, subtract the entered pre-tax contributions and modeled standard deductions, and apply the stored state and federal schedules. FICA is computed on gross wages. Not every pre-tax benefit has the same payroll-tax treatment, so this simplified input does not model those differences. Annual take-home pay subtracts the entered contributions and modeled taxes from wages; monthly take-home pay divides that result by 12.
The supported filing choices are single and married filing jointly. Local income taxes, tax credits, itemized deductions, self-employment income, part-year residency, and some state-specific adjustments are outside this model. Tax liability estimates are different from withholding calculated from a W-4 and payroll records.
Sales tax estimates
Sales tax equals the taxable purchase amount multiplied by the entered percentage divided by 100. The total adds that tax to the purchase amount. State pages prefill a reference average combined rate; an average is not an address lookup. Enter the applicable rate yourself and check exemptions, shipping treatment, and special taxes with the relevant authority.
Worked examples
Examples on state calculator pages use the same calculation functions as the interactive tools. Income examples use a single filer earning $60,000 per year with no pre-tax contributions. Sales examples use a $100 purchase at the tool's default rate. They illustrate the model and its assumptions; they do not independently validate the underlying tax law.
Corrections and article dates
If a result or guide appears wrong, report it to ToolsDoc with the page URL, expected result, and an official reference where possible. Do not send Social Security numbers or tax documents. Article publication dates and subsequent revision dates are separate; a new build does not make an old article newly reviewed.
For a return, payment, or other financial decision, verify current rules with the relevant authority or a qualified tax professional. Read our terms for more details.