How these tea tools are built
Each calculator exposes its assumptions and uses editable inputs. Tea-specific tools begin with the library’s editorial brewing ranges; the caffeine planner identifies its FDA and study values; the altitude tool states its atmospheric model; and the cost tool shows its formula.
What no tea calculator can know
A tool cannot remotely measure a cup’s caffeine, judge leaf freshness, replace a product label, or determine what is medically appropriate for one person. Use the output as a repeatable starting point, taste the tea, and update the inputs with better information when you have it.