Caffeine calculator: milligram comparisons and Taiwan tiers
Milligram comparison (derived, never measured)
Enter the drink's caffeine milligrams (a label / self-reported value, never measured by this tool) against the FDA line (authorized paraphrase): 400 mg a day for most adults. Every comparison is derived, never measured: the line is an authorized anchor, your input is a label value, and their comparison is a derivation, not a measured equivalence.
FDA consumer page (fetched and checked 2026-09-18): for most adults, 400 mg a day — about two to three 12-ounce coffees — is an amount not generally associated with negative effects (authorized paraphrase, not a quote).
Trying/pregnant/breastfeeding: the current FDA page states no figure, only advises seeing a doctor (checked 2026-09-18). This calculator sets no pregnancy number line.
Taiwan tier demo
Enter mg per 100mL + drink type to see the tier: ≥20 exact / <20 ceiling (shows ≤ ceiling) / coffee-tea-cocoa ≤2 low caffeine. Instant sachets label the per-serving total. Rule text on the method page, S-TFDA-quote.
≥20: exact label
Caffeine ≥20 mg/100mL: labeled in mg per 100mL (exact value).
<20: ceiling label
Caffeine <20 mg/100mL: may be labeled “20mg/100mL以下” — a ceiling, not an exact value; the calculator shows ≤ ceiling.
≤2 (coffee/tea/cocoa): low caffeine
Coffee/tea/cocoa drinks at ≤2 mg/100mL may be labeled “低咖啡因”.
Instant sachets: total per serving
Powder products for reconstitution: labeled with total caffeine per serving (mg).