How many grams in a cup depends on what you measure. A cup of water weighs about 237 g, but a cup of all-purpose flour is roughly 125 g, and a cup of sugar is around 200 g. The volume is the same; the density is what changes the weight. Below you'll find a conversion table for the ingredients you'll most often see in recipes, plus FAQs covering US versus metric cups and how to measure accurately.
How to convert cups to grams
Multiply the cup amount by the ingredient's density per cup. For water and milk-like liquids, 1 cup ≈ 237 g. For dry ingredients like flour, sugar, and cocoa, density varies — use the table below or a kitchen scale for precise baking.
It depends on the ingredient. 1 cup of water is about 237 g, 1 cup of all-purpose flour is about 125 g, 1 cup of granulated sugar is about 200 g, and 1 cup of butter is about 227 g. The volume is constant, but density changes the weight.
Is 1 US cup the same as 1 metric cup?
No. A US cup is 236.59 ml, while a metric cup (used in Australia, Canada, and parts of Europe) is 250 ml. That's about a 6% difference — large enough to matter in baking. This site uses the US cup unless you specify otherwise.
Why does 1 cup of flour weigh less than 1 cup of sugar?
Flour is loose and full of air pockets, so a cup of it weighs around 125 g. Sugar packs more tightly with smaller, denser crystals, so the same volume weighs around 200 g. Anytime you swap one for another by volume, you change the recipe by weight.
How accurate is converting cups to grams without weighing?
Good enough for everyday cooking, but not for precision baking. Cup measurements vary by 10–20% depending on how you scoop and pack the ingredient. For bread, pastries, and anything where ratios matter, a kitchen scale is faster and far more reliable.