A cup is a measure of volume, so the grams it holds change with the ingredient. A cup of all-purpose flour is about 125 grams, a cup of granulated sugar about 200 grams, and a cup of butter about 227 grams. The cups to grams converter stores these figures for each ingredient so you do not have to look them up.
Reference table
These are the widely used kitchen figures for one US cup:
| Ingredient | Grams per cup |
|---|---|
| All-purpose flour | 125 |
| Bread flour | 127 |
| Cake flour | 114 |
| Granulated sugar | 200 |
| Brown sugar (packed) | 220 |
| Powdered sugar | 120 |
| Butter | 227 |
| Vegetable oil | 218 |
| Milk | 245 |
| Water | 237 |
| Honey | 340 |
| Cocoa powder | 85 |
| Rolled oats | 90 |
| Rice (uncooked) | 185 |
Spoon-and-level dry ingredients rather than scooping, since packing the cup can add 10 to 15 percent to the weight.
Why density is the whole story
The reason there is no single cup-to-gram number is density: grams of weight packed into each millilitre of volume. Honey is dense, so a cup is heavy at 340 grams. Cocoa powder is airy, so a cup is light at 85 grams. Flour and sugar look similar in the cup but differ by 75 grams, because sugar crystals pack tighter than flour.
This is exactly why a single “1 cup = X grams” rule does not work. A reliable converter has to apply the density of the specific ingredient, which is what happens when you pick flour, sugar or butter before converting.
Dry and liquid measures
For liquids like milk, water and oil, a cup measured to the line is close to the gram figures above. For dry goods, the technique matters more, so weigh when you can. A kitchen scale costs little and turns vague cup measures into exact grams, which is the single biggest upgrade for consistent baking.
Convert your recipe
Enter any amount in the cups to grams converter, pick the ingredient, and read the grams. If you also need to resize the recipe, convert to grams first and then use the recipe scaler, which keeps the rounding clean.