Contact
Corrections, bug reports and requests for calculators still to be built all arrive in the same place. Corrections get answered first.
What to include
If a result looks wrong, include the calculator URL, units and a fictional example that reproduces the issue. Please do not send personal medical records, passwords or sensitive health details.
If the error is in the formula and not in the code, link the source you are working from. Several of these equations have competing published variants, and knowing which one you expect tells us whether we disagree about arithmetic or about which paper to follow.
What we cannot answer
Anything about your own health. We can explain what a formula does and where it came from, and that is the limit. Questions about your weight, your diet, a medication or a symptom need a doctor or a registered dietitian who can see your history. The disclaimer sets out the full position.