Sweet Rice

One US cup of sweet rice weighs 180 grams. Going the other way, 100 grams is about 0.56 cups.

Also called glutinous rice, sticky rice, mochigome, mochi rice, sweet white rice, sanpatong sweet rice, thai sticky rice, japanese sweet rice, gao nep.

TL;DR: 1 cup of uncooked sweet rice (also called glutinous rice, sticky rice, or mochigome) weighs about 180 grams. Medium confidence, based on Koda Farms and Nishiki medium-grain convergence. Thai long-grain sticky rice varieties pack slightly less densely at around 168 grams per cup, a 7 percent difference that reflects real grain-shape variance across producers.

Sweet rice is milled from glutinous short-grain or long-grain rice, a distinct variety of rice (Oryza sativa var. glutinosa) grown for its sticky, glue-like texture when cooked. Both common names are misleading. It is not sweet in the sugar sense; the 'sweet' descriptor is a translation artifact from Japanese and East Asian usage. And 'glutinous' refers to the sticky texture the cooked starch produces, not to gluten protein: sweet rice is naturally gluten-free. In Japan it is called mochigome, in Vietnam gao nep, in Thailand khao niao. The retail market in the US labels it as 'sweet rice' (typically Japanese-style short-grain from Koda Farms, Nishiki, Mogami), 'glutinous rice' (generic term used across many Asian brands), or 'sticky rice' (Thai and Southeast Asian long-grain style from Three Ladies, Butterfly Brand, Sanpatong-region producers).

The defining characteristic is the starch composition. Regular rice contains roughly 80 percent amylopectin and 20 percent amylose; glutinous rice is nearly 100 percent amylopectin, with almost no amylose. Amylose is the linear starch molecule that produces firm, separate cooked grains; amylopectin is the branched form that produces stickiness. This is why cooked sweet rice forms into a chewy paste (the base for mochi, ohagi, and Thai mango sticky rice) rather than staying as separate grains like long-grain white rice. When milled into flour, this same rice becomes sweet rice flour (see the separate sweet-rice-flour entry, which packs at 160 grams per cup).

The source data splits into two clusters by grain shape. Japanese short-grain sweet rice (Koda Farms and comparable brands) packs at 180 grams per US cup, matching the density of regular Japanese medium-grain rice like Nishiki. Rounder grains pack more tightly with fewer air gaps between kernels. Thai long-grain sanpatong sticky rice (Butterfly Brand, Mogami, Three Ladies) packs at about 168 grams per cup, roughly 7 percent lower, because elongated kernels leave more interstitial air. This variance is real product difference, not measurement noise, but it sits inside the 10 percent tolerance for milled-category ingredients and does not require publishing a range. The single figure of 180 grams per cup is anchored on Koda Farms as the dominant US retail brand for Japanese-style sweet rice, with the caveat that Thai long-grain buyers should expect closer to 168 grams per cup for their specific product.

King Arthur has no ingredient chart entry for sweet or glutinous rice. Their chart focuses on Western baking ingredients, and specialty Asian rices are outside its scope. This is not a King Arthur correction; it is a category KA simply does not publish.

For practical cooking, weigh sweet rice from the bag rather than measuring by volume, especially for mochi, ohagi, or Thai sticky rice recipes where the rice-to-water ratio determines final texture. The 12-gram spread between Japanese short-grain (180 g/cup) and Thai long-grain (168 g/cup) is enough to shift the finished texture, particularly in traditional preparations that soak the rice before steaming. Sweet rice absorbs less water during cooking than regular rice because its high amylopectin content limits gel network formation, so recipes typically call for a lower water ratio (about 1:1 to 1:1.2 rice to water for steaming, versus 1:1.5 to 1:2 for regular medium-grain rice).