Contact & report a calculation issue

Found a confusing explanation or a result that does not look right? Email [email protected] with the site name in the subject.

What makes a useful report?

• The page URL.
• The values you entered, in their original order.
• The result you expected and the result displayed.
• Your browser name, if a button or graph did not work.

Please do not send passwords, student names, grades, private homework portal links, or other sensitive details. We do not provide individual tutoring, grade assignments, or guarantee a response time.

For calculation assumptions, read our method. For data handling, read the privacy policy.