Why Cooking Measurements Are a Disaster (And the Math to Fix Them)

A recipe called for 200 grams of flour. I did not own a kitchen scale. I searched "200 grams flour in cups" and found answers ranging from 1.25 cups to 1.75 cups, depending on the source. That is a 40% variance. In baking, where ratios determine whether you get bread or a brick, a 40% difference is the gap between success and failure. The problem is fundamental: cooking measurements mix volume and weight, and the conversion between them depends on the density of the ingredient. One cup of flour does not weigh the same as one cup of sugar, and one cup of loosely scooped flour does not weigh the same as one cup of packed flour. Why volume measurements are imprecise A "cup" is a volume measurement: 236.6 milliliters (US customary) or 250 milliliters (metric/Australian). It tells you how much space the ingredient occupies, not how much mass it has. The problem is that most solid ingredients pack differently depending on how they are handled: All-purpose flour : Sifted : 120 grams per cup S