Professional bakers weigh everything. Home bakers measure by volume. The difference is why your cookies sometimes spread too thin, your bread doesn't rise, and the cake recipe you've made three times keeps coming out different. Volume measurements are imprecise in ways that matter enormously in baking.
Why Volume Measurements Fail in Baking
A "cup of flour" can weigh anywhere from 110g to 180g depending on how you scoop it. A lightly spooned cup weighs about 120g. The same cup scooped directly from the bag and packed slightly weighs 150g or more. That 25% difference in flour is enough to completely change a cookie's texture or a cake's structure.
Key Conversions to Know
- All-purpose flour: 1 cup = 120–130g (spooned and leveled)
- Granulated sugar: 1 cup = 200g
- Brown sugar (packed): 1 cup = 220g
- Powdered sugar: 1 cup = 120g (sifted) to 140g (unsifted)
- Butter: 1 cup = 227g = 2 sticks = 16 tablespoons
- Honey / maple syrup: 1 cup ≈ 340g
- Water / milk: 1 cup = 240g (liquids: ml ≈ grams)
💡 The spoon-and-level method: Spoon flour into your measuring cup until overflowing, then sweep a straight edge across the top. Never scoop directly from the bag — this packs 20–30% more flour into the cup.
How to Convert Any Recipe
Look up the gram weight for each ingredient (the density varies significantly — a cup of cocoa powder weighs very differently than a cup of oats). Use a kitchen scale set to grams. Tare (zero) between each ingredient if adding to the same bowl. Once you cook by weight, you'll never go back to washing multiple measuring cups.
When Volume Is Fine
For savory cooking — soups, stews, pasta sauces — volume measurements are perfectly adequate. The chemistry is more forgiving and small variations don't cascade into failure. But for bread, pastry, cakes, cookies, and anything that relies on a specific ratio of flour to fat to liquid to leavening: weigh it.
Scaling Recipes Up or Down
Grams make scaling trivial. Doubling a recipe is multiplication; halving it is division. With cups and tablespoons, you're converting fractions of fractions ("one-third of 3/4 cup"). With grams, it's 200g → 100g. Simple.