Cups to Grams Calculator
Convert American cup measures into grams. Choose your ingredient first, because a cup of flour weighs far less than a cup of honey.
US legal cup = 240 ml
Different ingredients weigh different amounts for the same volume, so pick the right one.
Answer
1 US cup plain flour = 125 g
Handy amounts for this ingredient
Reference and detail
What one cup weighs
| Ingredient | One US cup |
|---|---|
| Plain flour | 125 g |
| Caster sugar | 200 g |
| Icing sugar | 120 g |
| Butter | 227 g |
| Water | 240 g |
| Rolled oats | 95 g |
There is no single answer to “how many grams in a cup”. It depends entirely on what is in the cup.
Why the ingredient matters
A cup is a measure of space, not weight. A US cup of plain flour is about 125 g, while the same cup of caster sugar is about 200 g and water is 240 g. Any converter that ignores the ingredient will give you the wrong answer.
How to measure a cup of flour
Spoon the flour into the cup and level the top with a knife. Scooping straight from the bag packs it down and can add 20% more flour than the recipe wanted.
Questions and answers
Questions about converting cups to grams
Does one cup always weigh the same number of grams?
No. A cup is a measure of volume, so its weight depends entirely on what is in it, a cup of flour is much lighter than a cup of sugar, and a cup of honey heavier still.
Always pick the exact ingredient in the calculator above rather than using a generic cup-to-gram figure.
Why do two recipes give different gram weights for a cup of the same ingredient?
The way the ingredient was measured matters as much as the ingredient itself. A cup of flour spooned in and levelled weighs less than one scooped straight from the bag and packed down.
Brown sugar is the opposite: recipes usually mean it lightly or firmly packed, and that changes the weight noticeably.
Is a US cup or a UK cup being used in the conversion?
The calculator above converts US cups, since that is what almost all cup-measure recipes online mean. Older British cookbooks sometimes use an imperial cup, which is a different size. Check the recipe's origin if the result looks off.
Should I convert to grams or just measure in cups?
Weighing on scales is more accurate than measuring by volume, especially for flour, where packing can shift the amount by a fifth. Convert once with this calculator, then weigh from the gram figure for a more reliable result.
Guidance
Read the full guide
- Cups to Grams: Why the Ingredient MattersA cup measures space, not weight, so one cup of flour and one cup of sugar are nowhere near the same. Here is what that means when you follow an American recipe.