FreeKalc publishes calculators and guides about tax, salaries and personal finance. Because this is money information, we hold every page to the same standard: rates must be traceable to an official source, estimates must be labelled as estimates, and updates must be dated.
Where our numbers come from
- United States: federal income tax brackets and FICA rates from the Internal Revenue Service; state income tax rates from each state's department of revenue (for example the California Franchise Tax Board and the Michigan Department of Treasury).
- United Kingdom: Income Tax bands, National Insurance rates and student loan thresholds from HM Revenue & Customs, plus gov.uk SDLT guidance for stamp duty.
- Europe: income tax and social contribution rates from national authorities — the German Federal Ministry of Finance, the Irish Revenue, the Dutch Belastingdienst — and VAT rates from the European Commission.
Review process
Every calculator page states the tax year or rate year its numbers apply to. We re-verify all rates at least once a year, and within weeks of major budget or Finance Act announcements that change take-home pay. When a rate changes, we update the page and its structured data together, so a page never shows two different figures for the same year.
Estimates, not advice
Take-home pay depends on personal circumstances — pension contributions, health premiums, local taxes and filing status all move the number. FreeKalc results are estimates for a standard single filer unless the page says otherwise, and the tools are general information, not financial, tax or legal advice. For decisions that matter, confirm with a qualified professional or your tax authority.
Corrections
If you spot a wrong or out-of-date figure, tell us via the contact page and we will correct it. Significant corrections are made within days and the page's review date is refreshed.
Related pages
- About FreeKalc — who we are and what we build
- Contact — questions, corrections and feedback
- Blog — guides and explainers from the team
Last reviewed: October 2026 by H. Jhon, founder and editor.