How we handle messages
Every message that arrives through the addresses above or through the form goes into one inbox. That inbox is read by a real person, usually within a working day and always within two. There is no chatbot on the other side, no ticket system that quietly files your message away, and no automated reply pretending to be a human. If you wrote to us, a person on our end reads what you wrote.
What happens next depends on what you sent. A bug report gets checked against the tool you mentioned: we reproduce the numbers you entered, look at the formula the tool uses, and compare the two. If there is a mismatch, we fix it and write back to let you know. If the result is correct but the explanation was unclear, we update the wording on the page and thank you for pointing it out.
A feature suggestion goes onto a running list that we review every few weeks. We do not reply to every suggestion with a promise, because we do not want to promise something we cannot deliver. But we read them all, and the ones that keep coming up from different people are the ones we tend to build next.
A partnership message is read carefully and answered properly. We are a small operation, so we cannot say yes to everything. But we would rather have an honest conversation than a slow silence, and every genuine enquiry gets a genuine reply.
What we ask of you
A few small courtesies make the whole process work better:
- Be specific. "The BMI calculator is wrong" is harder to act on than "I entered 70 kg and 1.75 m, and the tool said 22.9 when WHO's example says 22.86." Both are valid reports; one is far easier to check.
- Do not send sensitive information. There is no need to include your ID number, card details, medical records, or full home address in any message. If your question really does need context like that, describe the shape of the situation rather than the exact details.
- One topic per message. If you have three separate issues, three short messages are easier to track than one long one.
- Give us a way to reply. If you write from an address you do not check often, please mention an alternative. If you wrote anonymously on purpose, we will read the message but we will not be able to follow up.
- Be patient. Two working days is our normal reply time. It is sometimes faster, occasionally slower when volume is high. It is never ignored.
What we will not do with your message
We will not add your email address to a marketing list. We will not share your message with anyone outside the small team that reads the inbox. We will not use your name, your writing, or the details of your enquiry in any public page on the site without your explicit permission. The full picture of how we handle personal information is set out in our Privacy Policy, which is worth a read if you want the complete version.
One small exception worth mentioning: if a message contains a threat, illegal content, or an attempt to abuse the site, we may need to retain it in order to act on it, including reporting it to a relevant authority if the situation warrants. That has never happened so far, and we hope it never does. But it is only fair to say it plainly rather than pretend there is no such line.
About this form
When you fill in the form above and click Send, your email application opens with a message already composed. The "To" field is filled in based on the topic you selected, so a bug report goes to the bug inbox and a partnership enquiry goes to the partnership inbox. You can read the whole message before sending it, edit anything, or cancel if you change your mind.
We chose this approach on purpose. It means your message is sent from your own email account, through your own provider, with no third-party form processor in between. Nothing is uploaded to a server you did not choose. Nothing is stored anywhere before you press Send. When the message arrives on our side, it arrives as ordinary email, and it sits in the same inbox as everything else.
If your device does not have an email application configured, the form will tell you so, and you can simply copy the address from the "Ways to reach us" section above and write to us from any mail service you already use. Gmail, Outlook, Proton, Yahoo, whatever you prefer — they all work.
Before you write — have you checked the FAQ?
Some of the most common questions have already been answered in detail on our FAQ page. If your question is about how a tool works, whether a result is accurate, what data is collected, or how to use the site offline, there is a good chance the answer is there. A quick look before writing often saves both of us a round trip.
If you have read the FAQ and your question is still not covered, that is exactly the kind of message we want to receive. It tells us where the documentation is falling short, and it often leads to a new entry being added.
Thank you for taking the time
Sending a message about a free tool is a small act, and we do not take it for granted. Every correction makes the site more accurate for the next person. Every suggestion points to something worth building. Every quiet note about something that worked well is genuinely encouraging, even when it does not need a reply.
If there is something on your mind about the site — a bug, an idea, a question, or just feedback — please use one of the channels above. We are listening.