How do I determine the amount of water I need to use with my eletric rice cooker
Rice cookers usually use the "absorption method", in which by the end of the cooking, all of the water has been absorbed into the rice.

If, by the time the rice is the texture you want, there is still liquid in the pan, then you used too much water. But it's OK; just pour the excess away and leave it a couple of minutes for the rest to absorb/evaporate.

If there is no liquid left, but the rice is not as soft as you would like, then you did not add enough water. Sprinkle with boiling water and allow to cook for longer.

With the absorption method, rice is pretty foolproof: twice as much water as rice -- by volume, and one teaspoon of salt per cup of rice. The packet will tell you how long your rice should take.

Things that can go wrong when using the absorption method in an ordinary pan:


burning due to having the heat too high when there's not much liquid left. Once the water is boiling, you only need the tiniest amount of heat.
burning due to cooking for too long - don't forget to check when the time's up!
loss of water as steam - due to cooking without a lid, and boiling too vigorously. Turn the heat right down, leave the lid on, don't peek until towards the end of the cooking time.