A cup of flour is not an amount
Flour compresses. The standard we (and King Arthur's test kitchen) use is 120 g per cup, spooned and leveled — flour fluffed, spooned into the cup, swept flat. Dip the cup into the bag instead and it packs: King Arthur's own guidance puts a scooped cup around 150 g. That's 25% more flour from the identical written instruction — in a three-cup cake recipe, most of an extra cup, which is the difference between tender and dry. No oven setting fixes an ingredient list that was never measured.
Grams have no technique. 120 g of flour is 120 g in every kitchen, every humidity, every level of hurry. That's the entire case: weight removes the only wildly unreliable variable in home baking.
Same cup, very different grams
The second problem with cups: a cup of one ingredient tells you nothing about a cup of another. One US cup, by our tested density table:
| Ingredient (1 US cup) | Weight | Note |
|---|---|---|
| All-purpose flour | 120 g | spooned & leveled |
| Cake flour | 120 g | spooned & leveled |
| Granulated sugar | 198 g | — |
| Brown sugar (packed) | 213 g | packed |
| Powdered sugar (unsifted) | 113 g | — |
| Cocoa powder (unsweetened) | 84 g | — |
| Butter | 227 g | 2 sticks |
| Honey | 340 g | — |
| Rolled oats (old-fashioned) | 89 g | — |
Cocoa to brown sugar is a 2½× swing on the same "cup". Every figure above links to a full conversion chart for that ingredient, and all of them come from the sourced density table that an automated test checks against King Arthur's published chart on every change.
Convert as you read
You don't need gram-native recipes to bake by weight. Keep the recipe you love, and convert each volume line as you go — 40+ ingredients, cups, tablespoons and ounces in both directions:
Result
120 g
The workflow that makes weighing faster, not slower
- One bowl on the scale, tare between ingredients. Flour, tare, sugar, tare, cocoa — no measuring cups to level or wash. This is why weighed baking is quicker, not just more accurate.
- Pencil the grams onto the recipe the first time. Converting is a one-time cost per recipe; after that it's gram-native forever. (The converter's share links are handy for keeping a family recipe's conversions.)
- Butter needs no cups at all. US sticks are printed with tablespoon marks and weigh 113 g each — the butter converter translates sticks ↔ cups ↔ grams in one view.
- Keep spoons for the small stuff. A teaspoon of vanilla or salt is below what a 1 g kitchen scale resolves confidently. Weigh the structure (flour, sugar, fat, liquid); spoon the seasoning.
When cups are genuinely fine
Honesty cuts both ways: plenty of cooking tolerates volume happily. Liquids in a jug are consistent; a soup doesn't care about 10% either way; and rustic bakes with forgiving ratios (crumbles, pancakes) survive cup measurement. The scale earns its counter space where ratios are tight — cakes, cookies, pastry, macarons, bread — which is exactly where "it came out dry/dense/flat" complaints live.