It honestly depends on the type and quality of the rice you're using. For most types of rice, 1 part rice to 2 parts water is a good starting point. However, some types of rice are better with a ratio of 1:1.5 or 1:2.5. Factors that will affect the amount of water used are: age (the older it is, the more water it will need), quality, and whether or not you soaked it (soaked rice requires less water). I suggest experimenting with whatever rice you cook with most often; once you know the proper ratio for your brand, you should be able to translate that into this recipe.