Cups to grams, by ingredient
A 'cup' is a measure of volume, but UK recipes and kitchen scales work in grams. Because ingredients have different densities, this converter uses a per-ingredient density to turn US cups, millilitres or UK tablespoons into an accurate gram weight.
Weight of plain / all-purpose flour
125 g
Using a density of 0.53 g/ml
- In ounces
- 4.42 oz
- Volume
- 237 ml
American recipes measure by volume; British kitchens weigh by the gram. That mismatch is why a beautiful-looking US cookie recipe can fall flat in a UK oven — the conversion was done with a one-size-fits-all number that ignored what was actually in the cup. Flour, sugar, butter and honey all pack very differently, so the only reliable approach is to convert each ingredient using its own density.
This tool does exactly that. It first turns your amount into millilitres (a US cup is 236.588 ml, a UK metric tablespoon is 15 ml), then multiplies by the ingredient's density in grams per millilitre. A cup of cocoa powder, which is light and airy, comes out near 97 g, while the same cup of honey lands well over 300 g. The gram figure is the one to trust when you reach for the scales.
Keep in mind that baking rewards weighing over measuring. Cups are quick, but two cooks can scoop the same flour and be 20% apart. If a recipe matters — a birthday cake, a first loaf — convert to grams here, weigh it out, and you remove the biggest source of variation in the whole bake.
Frequently asked questions
- Why doesn't one cup always equal the same number of grams?
- Because a cup measures volume, not weight. A US cup of plain flour is about 125 g, but a US cup of honey is around 336 g — the honey is far denser. That's why a single 'cups to grams' number found online is so often wrong.
- Are these US cups or UK cups?
- US cups, at 236.588 ml each — the size assumed by almost all online recipes. A traditional UK 'breakfast cup' is roughly 284 ml, so if a vintage British recipe specifies cups, expect slightly larger quantities.
- How accurate are the densities?
- They're solid kitchen averages, accurate to within a few percent for everyday baking. Real flour varies with how tightly it's packed and how humid your kitchen is, so for bread and pastry a £10 set of digital scales will always beat any cup measure.
- Should I spoon or scoop my flour?
- Spoon it into the cup and level off with a knife. Dunking the cup straight into the bag compacts the flour and can add 20% more weight than the recipe intended — the single biggest cause of dense, dry bakes.
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