Cups to Grams: Why Your Flour Measurement Is Probably Off by 25%
July 3, 2026
Two bakers follow the same cookie recipe. One gets tender, chewy cookies; the other gets dry hockey pucks. Same recipe, same oven — the difference was how they filled the measuring cup. A cup of flour can weigh anywhere from 120 g to 160 g depending on whether you spoon it in gently or scoop straight from the bag. That’s up to a third more flour without changing a single word of the recipe.
This guide explains why cup measurements drift, what common ingredients actually weigh, and how to convert any recipe to grams. For instant answers, the cups to grams converter covers 100+ ingredients and even accounts for how you measured.
Why a cup isn’t a fixed amount
A cup measures volume, but recipes care about mass. For liquids the two track each other closely — water is water. For dry ingredients, how much fits in the cup depends on how tightly the particles pack:
- Flour compresses easily. King Arthur Baking’s standard is 120 g per cup when you fluff the flour, spoon it into the cup and level it off. Dip the cup into the bag and sweep, and you compact it to 140–160 g. (America’s Test Kitchen actually standardises on 140 g per cup because that’s what dip-and-sweep yields — which is why their recipes and King Arthur’s assume different cups.)
- Brown sugar is usually meant to be packed — 213 g per cup — but loosely filled it’s around 145 g. The recipe rarely tells you which its author intended.
- Powdered sugar sifts down from 113 g (unsifted) to about 100 g (sifted). Whether you sift before or after measuring changes the result.
Grams have none of this ambiguity. 120 g of flour is 120 g of flour, no matter how it got onto the scale.
Which cup, exactly?
Even the cup itself isn’t one thing:
- The US legal cup — the one on US nutrition labels and the one modern US measuring cups are built to — is defined by the FDA as exactly 240 ml.
- The traditional US customary cup (half a US pint) is slightly smaller at about 237 ml.
- The metric cup, used in Australia, New Zealand and most metric-cup cookbooks, is 250 ml — about 4% larger than the US cup.
A 4% difference won’t ruin most dishes, but it compounds: follow an Australian recipe with US cups across flour, sugar and liquid and the ratios all shift in the same direction. The converter lets you switch between the 240 ml US cup and the 250 ml metric cup so the weights stay honest either way.
Cups to grams: the chart
Weights per US cup (240 ml), based on King Arthur Baking’s ingredient weight chart and USDA FoodData Central — the same data behind our converter.
| Ingredient | 1 cup |
|---|---|
| All-purpose flour (spooned & levelled) | 120 g |
| All-purpose flour (scooped) | ~142 g |
| Bread flour | 120 g |
| Whole wheat flour | 113 g |
| Granulated (white) sugar | 200 g |
| Brown sugar (packed) | 213 g |
| Powdered / icing sugar (unsifted) | 113 g |
| Butter (2 sticks) | 227 g |
| Honey | ~340 g |
| Cocoa powder (unsweetened) | 84 g |
| Chocolate chips | 170 g |
| Milk | 244 g |
Notice the spread: a cup of feather-light cocoa weighs 84 g while a cup of honey weighs about four times that. This is why a single “1 cup = X grams” number — which many conversion sites still publish — is meaningless without naming the ingredient.
One number worth memorising: the butter stick
US butter is mercifully standardised: 1 stick = ½ cup = 8 tablespoons = 113 g (4 oz). Two sticks make a cup at 227 g. If you’re working from a European 250 g block instead, the butter converter translates sticks, cups, tablespoons and grams in any direction.
How to measure flour if you don’t have a scale
Until the scale arrives, mimic the method your recipe’s author used. For most modern US recipes (King Arthur standard):
- Fluff the flour in its container with a fork or whisk.
- Spoon it into the measuring cup — don’t shake or tap the cup.
- Level the top with the back of a knife.
That gets you close to 120 g per cup. Whatever you do, don’t scoop the cup through the bag: that’s how a 25% overshoot happens, and dense, dry bakes follow.
The case for a $15 kitchen scale
A digital scale ends the guesswork entirely, and it makes baking easier, not fussier: set the bowl on the scale, zero it, pour to the number, zero again for the next ingredient. One bowl, no cups to wash, and your results become repeatable — the same recipe gives the same crumb every time.
Pair the scale with the cups to grams converter to translate your old cup-based recipes into weights once, note the grams in the margin, and they’re fixed forever. If you’re scaling a recipe up or down at the same time, the recipe scaler will convert and multiply in one step — and for bread bakers, the baker’s percentage calculator takes gram-based recipes to their logical conclusion.