Cups and Grams: Why Recipes Disagree
Anyone who cooks from both British and American sources eventually hits the conversion problem. A recipe says one cup of flour, another says a hundred and twenty grams, a third says a hundred and forty-five, and all three claim to be the same thing.
Why the Numbers Vary
They vary because a cup measures volume and flour is compressible. How much fits depends entirely on handling, and different authors assume different methods.
The spoon-and-level method, spooning flour lightly into the cup and levelling with a knife, yields around a hundred and twenty grams. Dipping the cup directly into the bag compacts the flour and yields closer to a hundred and fifty. Both are described as one cup, and neither author is wrong within their own convention.
Weight sidesteps this entirely, which is why serious baking books have moved to grams and why kitchen scales, such as those in the Escali range, have become standard equipment for anyone baking from varied sources.
Rough Conversions Worth Knowing
- Plain or all-purpose flour: about 120 to 125 g per cup, spooned and levelled
- Granulated sugar: about 200 g per cup
- Brown sugar, packed: about 220 g per cup
- Butter: about 227 g per cup, which is two American sticks
- Water and milk: about 240 g per cup, since density is close to one
- Cocoa powder: about 85 g per cup, which surprises people
These are approximations. Where a recipe gives grams, use the grams rather than converting to cups and back.
Cups Are Not the Same Size Either
An American cup is roughly 240 millilitres. A metric cup, used in Australia and elsewhere, is 250. A British cup, in older recipes, is often 284 millilitres, derived from the imperial half pint.
The difference between an American and an Australian cup is small in one ingredient and significant across a whole recipe.
Liquids Are Simpler
For water, milk and most thin liquids, volume and weight are close enough to interchangeable: one millilitre weighs approximately one gram.
This does not hold for oil, which is lighter, or honey and syrup, which are considerably heavier. Weighing sticky ingredients is also far easier than measuring them, since none of it clings to a measuring spoon.
Practical Approach
Follow the recipe in its own units where possible. Where conversion is unavoidable, convert once, note the gram figures on the recipe, and use those in future.
Where a recipe gives both and the numbers do not match your reference, trust the weight. It is the figure the author actually tested with, and the cup measurement is usually a conversion added afterwards for readers.
