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 estimated 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
One cup in grams: ingredient comparison
Grams = cups × millilitres per cup × density in g/ml. A US cup of plain flour is approximately 125 g using this tool's 0.53 g/ml assumption; a 250 ml metric cup is approximately 133 g.
| Ingredient | 1 US cup | 1 metric cup |
|---|---|---|
| Plain / all-purpose flour | 125 g | 133 g |
| Caster sugar | 201 g | 213 g |
| Brown sugar (packed) | 220 g | 233 g |
| Butter | 227 g | 240 g |
| Milk | 244 g | 258 g |
| Honey | 336 g | 355 g |
| Vegetable oil | 218 g | 230 g |
| Uncooked rice | 201 g | 213 g |
| Cocoa powder | 97.0 g | 103 g |
| Water | 237 g | 250 g |
Estimates use this calculator's density assumptions and round to the displayed precision. Packing and moisture affect the actual weight; use the recipe's gram quantities when provided.
Sources, assumptions & calculation methodsHow to use this result
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?
- Choose US cups (236.588 ml, the default) or metric cups (250 ml). Check which measure the recipe uses. A traditional imperial cup is approximately 284 ml and is not one of this tool's cup presets.
- How accurate are the densities?
- These are approximate density assumptions, not laboratory measurements or a guaranteed tolerance. Packing, brand and moisture affect the result. Use the recipe author's gram weights when available, and weigh ingredients for repeatable baking.
- 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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