Rice in grams, and the rice-cooker cup that is not a cup

A rice-cooker cup holds about 150 grams of uncooked white rice, and a US cup holds 185. Reaching for the wrong one is the commonest rice-measuring mistake in an English-speaking kitchen, because the little plastic cup in the cooker box is a Japanese go, not the cup your recipe means.

A US cup of rice, and the half cup no one should double

Uncooked white long-grain rice weighs 185 g to the US cup, measured by the USDA. It is the only authority that prints a whole cup of uncooked rice. King Arthur does print a whole cup, but of cooked brown rice at 170 g, which is a different food that has swollen in water and cannot be read back into a dry measure. On the dry rice a recipe means, King Arthur stops at a half cup of 99 g, and we do not double a published half to build a whole one, which is just as well: doubling gives 198 g, 13 more than the USDA read. The choice to trust a measured cup over a doubled half is the kind of call the methodology page lays out. Going the other way, 200 grams of rice in cups is the weight where that doubled half lands.

Rice conversions in full

Density used: 0.78 g per ml, for raw white long-grain rice.

The rice-cooker cup is a go, not a US cup

Every rice cooker ships with a plastic measuring cup, and it is not a US cup. It is one go, the old Japanese rice measure of 180 millilitres, and it holds about 150 grams of uncooked white rice. The marks inside the cooker bowl are calibrated to it: fill rice to the line numbered 3, add water to the matching mark, and you have set 3 go to cook, near 450 grams of raw rice. Read those marks as US cups and you overshoot the water. Short and sticky rices weigh a little more in the same go, with mochi rice near 155 grams and no-rinse rice near 160, since a rounder grain packs the cup fuller.

Rice by the cup around the world

A US cup, a metric cup and a Japanese kitchen cup are three different volumes, and each holds a different weight of rice. Variety matters too: the same metric chart that reads 210 g for long-grain rice puts arborio at 220 and sushi rice at 225, because a stubbier grain settles tighter.

The Japanese kitchen cup and the go are both Japanese and easy to confuse: the kitchen cup is 200 millilitres for general cooking, the go is 180 and belongs to rice alone. A go of raw rice is about 150 grams, lighter than any of the three cups above. Both sit in cup sizes around the world, alongside the drinking glasses and yogurt pots other countries measure with, and Japanese recipe measurements decodes the rest of a Japanese ingredient list.

Questions about rice weight

How many grams is a cup of uncooked rice?

185 g for a US cup of white long-grain rice, from the USDA. It is the only authority that prints a whole cup of uncooked rice; King Arthur stops at a half cup of 99 g, and doubling that would read 198, not 185.

What is the cup that comes with a rice cooker?

A go, the Japanese rice measure of 180 millilitres. It holds about 150 g of uncooked white rice, and the numbered marks inside the cooker bowl count go, not US cups. Fill it to line 2 and you have cooked 2 go, near 300 g of raw rice.

Is a cup of rice the same weight cooked?

No, and this page is raw rice only. Rice roughly triples in weight as it absorbs water, so a cup of raw rice becomes about three cups cooked. Recipes that give a raw cup and a cooked cup are not talking about the same thing.

Sources

USDA FoodData Central SR Legacy for the 185 gram US cup. Sanitarium for the 210 gram metric cup and the arborio and sushi figures. The Kagawa Nutrition University standard tables, as reproduced by Benricho, for the 170 gram Japanese cup and the go that holds 150 grams of white rice. Full citations on the sources page.