While rice cooker preparation times vary by the brand of rice cooker and the amount being prepared, it typically takes about 30 to 35 minutes to make a full pot of white or brown rice. Different types of rice require different amounts of water for cooking.
Soft rice requires 2 cups of water for every cup of rice. Firm rice, such as Basmati, requires 1.5 cups of water to 1 cup of rice, and brown rice requires 2 cups plus 2 tablespoons of water for each cup of rice. Some types of rice have a tendency to boil over when prepared in rice cookers. Rinsing rice three to four times before adding it to a rice cooker washes away the excess starch that can cause rice to boil over.