A US cup of granulated sugar weighs about 200 g. That is the USDA figure, and King Arthur Baking’s chart says 198 g, so for once the published numbers almost match. In the other cups shown above, the same sugar comes to about 211 g in a metric cup, 169 g in a Japan cup and 152 g in a Taiwan rice cup.
Why the weight depends on how you measure
Granulated sugar is one of the most forgiving ingredients to measure by volume. Its crystals are hard, fairly uniform and flow freely, so they do not trap much air and they barely compress. Pouring it into the cup, spooning it in or dipping the cup into the bag all end up close to 200 g once you level the top. That is why the range shown above is so narrow compared with flour.
The sugars around it behave very differently, and that is where mistakes happen. Brown sugar is sticky and full of small pockets, so recipes ask for it packed: about 220 g per US cup when pressed firmly, but only about 145 g if you just spoon it in. Powdered sugar goes the other way; it is mostly air when sifted, about 100 g per cup, and about 120 g unsifted. If a recipe says “sugar” with no qualifier, it nearly always means granulated, and the 200 g figure applies. Old sugar that has formed lumps should be broken up first, since clumps leave gaps in the cup.
Which cup does your recipe use?
In a US recipe, 1 cup of sugar means the 236.6 mL US cup and about 200 g. Australian recipes use the 250 mL metric cup, so their cup of sugar is roughly 11 g heavier. Japanese recipes use the 200 mL cup, but for sugar they more often give grams or spoons. Taiwan baking recipes are usually written in grams, so a conversion is mostly needed when you follow an American or Australian recipe.
Small amounts are usually given in spoons. A US tablespoon holds about 12.5 g and a 15 mL metric tablespoon about 12.7 g, so the difference between those two spoons is negligible. The 20 mL Australian tablespoon is another matter at about 16.9 g.
Tips for measuring by volume
- Fill the cup to overflowing, then sweep the excess off with a straight edge; there is no need to pack or tap.
- Keep sugar in a closed container so it stays free-flowing.
- Check which sugar the recipe means before measuring; packed brown sugar and sifted powdered sugar are far from 200 g.
- For syrups or candy, where the ratio of sugar to water controls the result, weigh rather than measure.