I've been using this foolproof method to make medium or shortgrained white rice for years. Quantities for two people:

* One Nutella glass[1] worth of rice (don't overfill, the "peak" of the rice should be in line with the rim

* Wash the rice in the rice cooker bowl several times, drain by tipping the water out without letting the rice flow out. You'll be left with a small amount of water in the bowl

* One full Nutella glass worth of water.

Put the rice cooker on! You can also add salt/coconut milk/etc to taste without adjusting the above.

[1] https://i.pinimg.com/originals/74/ac/35/74ac3541abbba4f63b99... Eat the Nutella first if required!