Observation: Coffee studies often report (in headlines and abstract and body) consumption in terms of <i>cups</i>.<p>At best, this refers to a standardized 250 ml or 8 oz measuring cup (unfortunately, still rarely what "a cup of coffee" generally means to those who read these headlines and adjust behaviour as a result).<p>At worst, the term is used to allow for ambiguity and variance expected in self-reporting.<p>I recognize there are many other variables that are even harder to measure than beverage volume, like mg of caffeine or diterpenes or antioxidants. But "cups" just seems so loose.<p>Related question: Is there a somewhat accurate amateur method of measuring caffeine content? I vary my beans and roasts and method a fair bit for fun and taste. e.g. various beans, light vs medium vs dark roasts, varying apparatus, mass of beans per "cup", filter types, and brewing time. I would like to have insight into how much caffeine I'm consuming.