Privacy policy

Last updated: 18 October 2026

Calculations

Every calculator on www.zhaku.net runs entirely in your browser using JavaScript. The amounts, rates, incomes and balances you type are processed on your own device and are never transmitted to our servers, logged, or stored anywhere by us.

Usage counters

When a calculator is used, the site increments an anonymous daily counter for that calculator (for example, "the VAT calculator was used 214 times today"). This counter contains no personal data whatsoever - no IP address, no identifier, no cookie, and none of the values you entered. It exists purely so we know which tools are worth improving.

Cookies, advertising and local storage

We do not set our own tracking cookies. Zhaku uses Google AdSense, which may use cookies and similar technologies to deliver, measure and personalise advertising. Google and its partners may use information about visits to this and other sites to show relevant adverts. You can learn about Google's advertising policies and controls at Google's advertising page and manage ad personalisation through Google Ad Settings.

Visitors in the UK and European Economic Area should be offered a consent choice before personalised advertising is used. When AdSense is enabled for live traffic, the publisher must configure Google's certified consent-management option for those visitors and provide the controls needed to change or withdraw consent. The only Zhaku-controlled local-storage entries remember your light/dark theme and, if you use the PWA banner, your install-banner preference; they never leave your device.

Server logs

Like virtually every website, our hosting provider keeps standard web-server logs (requested URL, timestamp, IP address, user agent) for security and troubleshooting. These are rotated automatically and are not used to identify visitors.

Messages sent to support

If you email [email protected], we receive the email address and any information you choose to include. We use it only to reply to your message and investigate a reported issue or suggestion. Please do not send sensitive financial information, passwords, card details or identity documents. We do not use support emails for marketing or sell them to anyone.

Changes

If this policy ever changes materially, the date above will be updated. Given how little data the site touches, big changes are unlikely.