Editorial Policy

Money decisions are real decisions, so every tool on FinanzTool has to be correct, transparent and up to date. This page explains who is responsible for the content, how we use AI, which sources we rely on and how mistakes are corrected.

Who is responsible

Omid Jamshidi is responsible for all content on FinanzTool. Every calculator and every text is reviewed by Omid Jamshidi before it goes online and again on each review date. The top of every tool page shows who reviewed it and the date of the last review.

How we use AI

We use AI tools to help write program code, draft texts and translate them into our five languages. AI does not decide what is published: Omid Jamshidi checks every formula, every figure and every worked example, tests the results and corrects the texts before publication.

How a calculator is built and tested

1. We start from a standard, publicly documented formula or from the official rules of the country concerned.
2. The method is explained on the tool page under "How it's calculated", together with a worked example.
3. Before publication, the results are tested with several sets of numbers, including edge cases such as zero or very large amounts, and compared with an independent calculation.
4. Most calculators show a first result computed on our server and then recalculate in your browser as you type. Both use the same formulas and are tested against each other.

Sources

• Tax rules: the official sources of each country, named on the tool page together with the tax year. For the salary calculator these are the IRS and the Social Security Administration (USA), GOV.UK (UK), the German Income Tax Act and the 2026 social insurance regulation (Germany), and the Spanish tax agency and Social Security rules (Spain).
• Exchange rates: the euro reference rates of the European Central Bank and live prices from the Kraken exchange.
• Crypto: live prices from the Kraken exchange; Bitcoin block data from mempool.space and blockstream.info.
• News: headlines from the public feeds of established news outlets, each linked to its source.

Reviews and updates

• Tools based on tax rules are reviewed at least once a year, as soon as the rules for the new tax year are published, and whenever a rule changes during the year.
• All other calculators are reviewed at least once a year.
• Live data updates automatically. If a source is unavailable, the page says so instead of presenting old figures as current.
• The review date on a tool page changes only when the tool has actually been checked.

Corrections

If you find a mistake, please tell us on the Contact page, ideally with the page, the numbers you entered and the result you expected. We check every report, correct confirmed mistakes as soon as we reasonably can and update the review date of the tool.

Advertising and independence

FinanzTool is financed by advertising and a few referral links. Both are labeled and kept separate from the content. Advertisers have no influence on our calculators, texts or results, and we do not accept payment for results or rankings.

Languages

Each language version is written for its own readers, with local terms, number formats and currencies. Where a rule applies only in one country, the page says so.

Disclaimer

Everything on this site is general information, not personal advice. See our Disclaimer.