Key points
- Volume measures how much space an ingredient fills; weight measures how much ingredient there is. For baking chemistry, the amount is what counts.
- King Arthur Baking’s ingredient chart lists one cup of all-purpose flour at 120 g but one cup of granulated sugar at 198 g — the same cup, very different amounts.1
- A scale with 1 g resolution, a tare (zero) button and roughly 5 kg capacity covers almost all home baking.
Space versus substance
A measuring cup tells you how much room an ingredient takes up. But ingredients pack differently: flour is fluffy and compressible, sugar crystals settle densely, and brown sugar is pressed down by design. The result is that “one cup” means a different amount of each ingredient — and, for flour, it can change with how you fill the cup.
Baking is chemistry. Gluten development depends on the ratio of flour to water, leavening depends on the ratio of acid to base, and texture depends on the balance of fat, sugar and flour. When the amount of one ingredient drifts, the ratios drift with it.
What a cup weighs: reference figures
King Arthur Baking publishes a widely used ingredient weight chart. A selection of its figures shows how much equal volumes can differ in mass:1
| Ingredient | Volume | Ounces | Grams |
|---|---|---|---|
| All-purpose flour | 1 cup | 4 ¼ | 120 |
| Bread flour | 1 cup | 4 ¼ | 120 |
| Whole wheat flour (premium 100%) | 1 cup | 4 | 113 |
| Granulated sugar | 1 cup | 7 | 198 |
| Brown sugar, packed | 1 cup | 7 ½ | 213 |
| Butter | 8 tablespoons (½ cup) | 4 | 113 |
| Water | 1 cup | 8 | 227 |
The chart itself recommends weighing: “For best results, we recommend weighing your ingredients with a digital scale.”1
Baker’s percentages: why grams unlock recipes
Professional bakers often express a formula as baker’s percentages: every ingredient is given as a percentage of the total flour weight, with flour fixed at 100%. A dough with 1,000 g of flour and 700 g of water is a 70% hydration dough. Working in weight makes it simple to scale a recipe up or down, compare two recipes, or adjust hydration deliberately — things that are awkward with cups and spoons.
What to look for in a kitchen scale
- 1 g resolution. Enough for flour, sugar, butter and liquids. For very small amounts such as yeast and salt in small batches, some bakers add a separate precision scale with 0.1 g resolution.
- Capacity around 5 kg (11 lb). Room for a mixing bowl plus a full batch of dough.
- A tare (zero) button. Lets you zero the bowl and add ingredients one after another.
- An auto-off you can live with. Scales that switch off quickly can lose your running total mid-recipe; check the stated auto-off time.
- A readable display. Large bowls can hide a display; some designs pull the display out to avoid this.
Frequently asked questions
Can I convert my favourite cup-based recipes to grams?
Yes. Use a reputable chart, ideally the one the recipe’s author used, and weigh the ingredients the first time you make it. Note the weights that give you the result you like.
Do liquids need weighing too?
Weighing liquids is convenient and consistent. King Arthur Baking lists one cup of water at 227 g; many scales also offer millilitre modes for water-like liquids.
Related buying guides
Our kitchen-scale buying guide is in final fact-checking and will appear here.
References
- King Arthur Baking. Ingredient Weight Chart. kingarthurbaking.com. Accessed October 28, 2026.
Last updated October 28, 2026. Spotted an error or an outdated price? See our corrections policy.