Why Volume-to-Weight Conversion Requires the Ingredient
A cup is a measure of volume — how much space something takes up. Grams measure mass. Bridging those two requires knowing one thing: how dense the ingredient is. And that varies dramatically.
Consider just three common baking ingredients:
| Ingredient | 1 cup (volume) | Grams | Oz |
|---|---|---|---|
| All-Purpose Flour | 240 mL | 120 g | 4.23 oz |
| Granulated Sugar | 240 mL | 200 g | 7.05 oz |
| Honey | 240 mL | 340 g | 12 oz |
A single "1 cup = X grams" table fails because the actual gram weight depends entirely on what's in the cup. That's why every conversion on this page is ingredient-specific.
How We Source Our Weights
Our primary reference is the King Arthur Baking Ingredient Weight Chart, which is the most widely cited professional standard for US baking. For ingredients not on King Arthur's chart, we use the USDA FoodData Central database. You can see the source for each ingredient in our full ingredient table.
The Measuring Technique Matters as Much as the Ingredient
The values above assume the "spoon and level" method: spoon the ingredient into the measuring cup with a separate spoon, then sweep a straight edge across the top. This is the standard professional method for dry ingredients.
If you scoop the measuring cup directly into a bag of flour, you compress it. A scooped cup of all-purpose flour can weigh 150–160 g — 25–33% more than the 120 g target. That extra flour makes cookies dense and biscuits tough.
For liquid ingredients (water, milk, oil), there is no technique variation — just fill to the line and the weight is consistent.
Common Baking Conversions (Reference Table)
| Ingredient | 1 cup | ½ cup | ¼ cup | 1 tbsp |
|---|---|---|---|---|
| All-Purpose Flour | 120 g | 60 g | 30 g | 7.5 g |
| Bread Flour | 120 g | 60 g | 30 g | 7.5 g |
| Cake Flour | 96 g | 48 g | 24 g | 6 g |
| Whole Wheat Flour | 113 g | 56.5 g | 28 g | 7 g |
| Almond Flour | 96 g | 48 g | 24 g | 6 g |
| Granulated Sugar | 200 g | 100 g | 50 g | 12.5 g |
| Brown Sugar (packed) | 213 g | 106 g | 53 g | 13.3 g |
| Powdered Sugar | 113 g | 56.5 g | 28 g | 7 g |
| Butter | 227 g | 113 g | 57 g | 14 g |
| Honey | 340 g | 170 g | 85 g | 21 g |
| Cocoa Powder | 85 g | 42.5 g | 21 g | 5.3 g |
| Rolled Oats | 90 g | 45 g | 22.5 g | 5.6 g |
US vs. UK vs. Metric Cups
A US cup is 240 mL (officially 236.6 mL). A UK/Australian cup is 250 mL — about 5% larger. A Japanese cup (合) is 180 mL. All conversions on this site use the US cup. If your recipe comes from Australia, multiply the gram result by 250/236.6 ≈ 1.056.
Worked Example: Scaling a Chocolate Chip Cookie Recipe
A recipe calls for 2¼ cups all-purpose flour, ¾ cup granulated sugar, ½ cup packed brown sugar, and 1 cup chocolate chips. Converting to grams:
- 2¼ cups AP flour: 2.25 × 120 = 270 g
- ¾ cup granulated sugar: 0.75 × 200 = 150 g
- ½ cup brown sugar (packed): 0.5 × 213 = 106.5 g
- 1 cup chocolate chips: 1 × 170 = 170 g
Weighing these on a scale instead of measuring by volume gives you the same result every time, regardless of how tightly or loosely the cup was filled.
Common Mistakes When Converting Cups to Grams
- Using a single generic weight — There is no universal "grams per cup." Always look up the specific ingredient.
- Forgetting measuring method — Scooped flour vs. spooned flour can differ by 30 g. Recipes from professional bakeries assume the spooned-and-leveled method unless stated otherwise.
- Treating all sugars the same — Granulated sugar (200 g/cup), brown sugar packed (213 g/cup), and powdered sugar (113 g/cup) are all very different.
- Assuming liquids are the same as water — Honey (340 g/cup) is 43% heavier than water (237 g/cup); using a water conversion for honey would badly undershoot the weight.
For deeper guidance on measuring technique, see our article on weighing vs. measuring cups and our guide to how to measure flour correctly.