Health Tools

Health tools are the ones we are most careful with. Every number here comes from a published equation fitted to a population, and every one of them is easier to over-read than to read. BMI was built to describe groups, not to judge a person, and it knows nothing about muscle or frame. The Mifflin–St Jeor equation behind the calorie tool is accurate to roughly ten percent for a typical adult and further out for anyone atypical. The water estimate is a rule of thumb with no strong evidence base at all, which is why it gives you a range rather than a target.

So each tool does the same three things: it shows you the figure, it names the method it used, and it tells you where that method is weak. Then it stops. None of them will tell you what to eat, what to weigh, or what to do next — that is a conversation for a professional who can actually examine you, and a calculator that pretends otherwise is doing something we are not willing to do.

Everything runs in your browser. Your height, weight, age and measurements are typed into a page and never leave the device — there is no account, no server and nowhere for any of it to go.