We answer questions about calculations, corrections, accessibility, advertising, and privacy. There is no phone line and no contact form, so nothing you send is stored in a database on this site.
Reporting a calculation problem
Include the address of the page and the exact values you entered. With those two things the result can be reproduced immediately; without them it usually cannot.
Accessibility
If a control is unreachable by keyboard, a contrast is too low, or a screen reader announces something confusing, describe what happened and which browser and assistive technology you used.
Privacy and advertising requests
Questions about the data this site handles, or about the advertising on it, go to the same address. The details are set out in the privacy policy and the cookie notice.