Last updated: October 26, 2026.
Calculator inputs
The calculator tools run locally in your browser. Their input values and calculated answers are not submitted to our server by the calculator code. The tools do not require a visitor account.
Contact messages
If you submit our contact form, we store the message and any optional name or email you provide privately in WordPress for the site administrator to review. We use it to handle the enquiry, investigate errors and, if appropriate, reply. Do not submit passwords, financial account details or other sensitive personal information.
A short-lived hash derived from the connecting IP address is used to limit repeated contact submissions for about one minute. Contact messages remain until the administrator removes them when no longer needed. You can request deletion through the contact form and provide enough information to identify your message.
Hosting and technical data
Hosting infrastructure may process ordinary request information such as IP address, requested page, browser information and timestamps for service delivery, security and troubleshooting. Hosting retention is controlled by the hosting provider and administrator. Calculator inputs are not intentionally included in these requests.
Cookies
The custom calculator interface does not require a tracking cookie. WordPress uses essential cookies for administrators who sign in. Additional services introduced later may require updates to this policy and applicable consent controls.
External links
Guides can link to external educational websites. Those sites have their own privacy policies. Following an external link takes you outside this website.
Your choices and questions
You may use the calculator without submitting a contact message. For a privacy question or a request concerning a message you sent, use our Contact page. This policy should be reviewed whenever the site introduces advertising, analytics or other data-processing features.