Cups to grams, for the ingredient you actually have
American recipes measure by volume and European recipes measure by weight, which would be a small annoyance if a cup were a fixed amount of anything. It isn't. A cup is a container, and what it weighs depends entirely on what you put in it.
That's the whole problem, and it's why most converters give you the wrong answer confidently.
Fractions are fine: 1 1/2, ½, 0.75
This is the part that matters. A cup of flour and a cup of honey are not the same weight, and most converters pretend they are.
Why a cup of flour and a cup of honey aren't the same
A cup holds 236.6 millilitres. Fill it with water and you get 237 grams, because water is the one ingredient where volume and weight line up neatly.
Fill it with anything else and the numbers come apart:
| One US cup of | Weighs about | Compared to water |
|---|---|---|
| Honey | 340 g | Nearly half again as heavy |
| Salt, table | 280 g | Much heavier than it looks |
| Butter | 227 g | Slightly lighter |
| Sugar, granulated | 200 g | A fifth lighter |
| Rice, uncooked | 185 g | |
| Flour, all-purpose | 120 g | Half the weight of water |
| Cocoa powder | 85 g | Mostly air |
| Desiccated coconut | 75 g | Barely a third |
A converter that assumes 237 g per cup will tell you a cup of flour is 237 grams. That's nearly double. In a cake that isn't a small error, it's a different cake.
The one that goes wrong most often
Flour, and not because the number's hard.
The 120 g figure assumes the flour was spooned into the cup and levelled off. Scoop the cup straight into the bag and you compact it, and the same cup can hold 140 g or more. That's a fifteen percent error introduced by nothing but technique, and it's the single most common reason a recipe that worked for someone else comes out dry for you.
If a recipe gives grams, use grams. Scales are cheap and they don't care how you hold them.
Spoons are fine, leave them alone
One thing this tool deliberately doesn't encourage: converting teaspoons and tablespoons into millilitres.
A teaspoon is a universal kitchen measure. A Dutch theelepel is 5 ml, a US teaspoon is 4.93 ml, and no dish in history has been ruined by the difference. When a recipe says a teaspoon of baking powder, the useful instruction is "a teaspoon". Turning that into "4.93 ml" makes it harder to follow and no more accurate.
Convert the cups, keep the spoons.
What this doesn't know
- How you packed it. Brown sugar packed firmly and brown sugar spooned loosely differ by a lot. The numbers here assume whatever convention each ingredient is normally measured by.
- Metric cups. This uses the US cup at 236.6 ml. Australian recipes often mean 250 ml, which is about six percent more.
- Your specific brand. Densities shift with grind, moisture and processing, so these are good working numbers rather than laboratory values.
For cooking, working numbers are enough. For bread and pastry, buy a scale.
Doing this inside a recipe
Converting one ingredient is fine. Converting a whole ingredient list, one line at a time, into a notes app, is the thing nobody actually finishes.
In Fork & Spoon a recipe carries both systems at once. A recipe imported in cups can be read in grams and back again with a switch, without retyping anything, and the amounts follow when you scale the servings. The recipe scaler here does the scaling part in your browser if that's all you need.
Questions
How many grams is a cup of flour?
About 120 g for plain all-purpose flour, 125 g for self-raising. It varies with how firmly the cup is packed: scooping straight from the bag compacts the flour and can add ten percent, which is why spooning it in loosely and levelling off is the usual advice.
How many grams is a cup of sugar?
About 200 g for granulated sugar, and about the same for brown sugar when it is packed down. Icing sugar is far lighter at roughly 120 g per cup, because it is mostly air.
Why do converters disagree with each other?
Because most of them assume water, where one cup is 237 ml and 237 g. That is right for water and wrong for everything else. A cup of honey weighs nearly a third of a kilo; a cup of desiccated coconut weighs 75 g. The ingredient decides.
Is a US cup the same as a metric cup?
No. A US cup is 236.6 ml and a metric cup, used in Australia and some European recipes, is 250 ml. This tool uses the US cup, which is what almost all American recipes mean.
Do teaspoons and tablespoons need converting?
Usually not. A teaspoon is a teaspoon in almost every kitchen. A Dutch theelepel and a US teaspoon are the same spoon, and the tiny difference in millilitres never matters for salt or baking powder. Turning "1 tsp salt" into "4.93 ml salt" makes a recipe worse, not better.