Contact & corrections

A clear report helps us make the next version more useful. Contact the publisher at:

Public contact details will be added before launch.

Report a calculation issue

Include the tool's page address, the numbers you entered, the result you saw, and the result you expected. Use invented example values if the original inputs are personal.

Suggest a correction

Point to the specific sentence or step and explain what is unclear. If your correction relies on a source, include a link that supports it.

Accessibility and privacy

You can use the same contact address for an inaccessible control, a readability problem, or a privacy question. Include your browser and device type when relevant.

Keep private information private

Please do not send passwords, student records, identity documents, payment information, or restricted examination materials. This site does not provide private tutoring or individual grade appeals.