THE BREW BENCH / UNDERSTAND
Know the range, not just a number.
Add source-backed ranges and known label values while keeping serving sizes and uncertainty visible.
A range is more honest for generic coffee
Two generic 12 fl oz brewed coffees total 226–494 mg using the FDA’s reported range. That is a range for planning, not a confidence interval or an upper bound on every coffee. A measured or labeled value for the drink in front of you is more specific. You can enter fractional servings only when scaling the same concentration; two different drinks need not have the same concentration.
EFSA’s general guidance for healthy adults discusses up to 200 mg in a single dose and up to 400 mg across a day; pregnancy guidance differs. These are population references, not a personal allowance or a target. Medicines, health conditions, sensitivity and sleep change the context. This calculator gives no personal safe/unsafe verdict and does not store your entries. Read the full caffeine guide.
Sources: FDA caffeine information; EFSA caffeine assessment. Checked 13 October 2026.