How We Calculate
Every number on gramstoocup.com comes from one weight per cup for each ingredient, the same formula and the same rounding rules. Here's exactly how it works.
The weights we use, and where they come from
| Ingredient | 1 cup | 1 tbsp | 1 tsp | How it's measured | Source | King Arthur |
|---|---|---|---|---|---|---|
| All-purpose flour | 125 g | 7.8 g | 2.6 g | spooned and leveled | USDA | 120 g |
| Granulated sugar | 200 g | 12.5 g | 4.2 g | scooped and leveled | USDA | 198 g |
| Butter | 227 g | 14.2 g | 4.7 g | packed, softened | USDA | 227 g |
| Brown sugar (packed) | 220 g | 13.8 g | 4.6 g | firmly packed | USDA | 213 g |
| Powdered sugar | 120 g | 7.5 g | 2.5 g | unsifted, spooned and leveled | USDA | 113 g |
| Milk | 244 g | 15.3 g | 5.1 g | liquid measuring cup | USDA | 227 g |
| White rice (uncooked) | 185 g | 11.6 g | 3.9 g | uncooked long-grain, leveled | USDA | 198 g |
| Honey | 339 g | 21.2 g | 7.1 g | liquid measuring cup | USDA | 336 g |
| Water | 237 g | 14.8 g | 4.9 g | liquid measuring cup | Density of water | 227 g |
| Rolled oats | 89 g | 5.6 g | 1.9 g | old-fashioned, leveled | King Arthur | 89 g |
| Bread flour | 120 g | 7.5 g | 2.5 g | spooned and leveled | King Arthur | 120 g |
| Cake flour | 120 g | 7.5 g | 2.5 g | spooned and leveled | King Arthur | 120 g |
| Whole wheat flour | 120 g | 7.5 g | 2.5 g | spooned and leveled | USDA | 113 g |
| Almond flour | 96 g | 6 g | 2 g | spooned, not packed | King Arthur | 96 g |
| Coconut flour | 128 g | 8 g | 2.7 g | spooned and leveled | King Arthur | 128 g |
| Cocoa powder (unsweetened) | 86 g | 5.4 g | 1.8 g | sifted if lumpy, spooned and leveled | USDA | 84 g |
| Peanut butter | 256 g | 16 g | 5.3 g | pressed in, leveled | Nutrition label (2 tbsp = 32 g) | 270 g |
| Chocolate chips | 170 g | 10.6 g | 3.5 g | scooped and leveled | King Arthur | 170 g |
| Cream cheese | 227 g | 14.2 g | 4.7 g | softened, pressed in | King Arthur | 227 g |
| Plain yogurt | 227 g | 14.2 g | 4.7 g | stirred, leveled | King Arthur | 227 g |
The formula
cups = grams ÷ grams per cup
grams = cups × grams per cup
Each ingredient has one weight per US cup, stored in a single data file. The converter, the charts, the guides and the answers in the text all read from that file, so the answer for 100 g of flour is the same on every page.
Where the weights come from
We use, in this order:
- USDA FoodData Central household measures. The US Department of Agriculture publishes the weight of a cup, tablespoon or teaspoon for thousands of foods.
- King Arthur Baking’s ingredient weight chart, for ingredients USDA doesn’t list in a useful form, such as bread flour, almond flour and old-fashioned oats.
- Physics, for water: 1 ml of water weighs 1 g, so a 236.6 ml cup weighs about 237 g.
The table above shows our figure, its source and King Arthur Baking’s figure side by side. The two sometimes differ by a few grams, mostly because King Arthur rounds to ounces and measures flour a little lighter. Where it matters, our pages mention both.
Units we use
- US cup: 236.588 ml (the US customary cup).
- Metric cup: 250 ml, used in Australia, Canada, New Zealand and the UK. The converter’s Metric option scales every weight by 250 ÷ 236.6.
- Tablespoon: 1/16 cup, 14.8 ml. Teaspoon: 1/48 cup, 4.9 ml.
- Butter stick: 113.4 g, a quarter of a 1 lb box.
- Ounce: 28.35 g (weight ounce, not fluid ounce).
How we measure
Weights assume standard American methods: flour, powdered sugar and cocoa are spooned into the cup and leveled; granulated sugar, rice and oats are scooped and leveled; brown sugar is firmly packed; butter and other fats are pressed in and leveled; liquids are measured in a liquid measuring cup at eye level.
How results are rounded
- Cup answers are rounded to the nearest fraction you can measure (¼, ⅓, ½, ⅔, ¾) plus the nearest ½ tablespoon or ½ teaspoon.
- When rounding moves the answer by more than 3%, we say “about”.
- “Measure it with” shows the combination of standard 1, ½, ⅓ and ¼ cups and spoons that comes closest with the fewest fills.
- Gram answers are rounded to the nearest gram.
Limits
A cup measure is never as exact as a scale. Humidity, brand, grind and how firmly you fill the cup can change the weight by 5–10%, more for flour. For bread, macarons and anything else that depends on precise ratios, weigh your ingredients.
Found a mistake?
Email [email protected] with the page and the number. We check and correct errors, and update the “last reviewed” date on the page.