About this site

JAJAMBO Tools is run by JAJAMBO, an independent developer of 35+ calculator and study apps for Android. This site brings some of those calculators to the web, free to use — in Japanese, German, Polish, Mexican Spanish and Vietnamese.

Method

Every calculator states the legal sources and the law revision date it is based on, directly on the page. Where a calculator has a companion Android app, the web version shares its parameters and formulas with the app engine and both are updated together — never one without the other. Parameter tables carry their effective dates and test vectors as comments in each page's source.

Independence

This is an independent site. It is not affiliated with any government agency, court or authority. Results are guidance, not legal or tax advice — each page carries a disclaimer in its own language.

Privacy

This site sets no cookies and loads no third-party scripts, ads or trackers. All calculations run locally in your browser; nothing you type is sent anywhere.

Contact

Feedback and corrections: macping@gmail.com