How much wattage does a rice cooker use?

[shivajikobardan]

We've a person who stays at rent, we find it uncomfortable to ask the wattage from them. So, I want to learn what's the wattage of rice cooker in general? Is 700Watt a good value to predict the electricity charge?

[Ian.M]

Most of the energy is used during the initial heat-up, to bring the water from ambient temperature to boiling point.  For the same volume of water, this is largely independent of the rice cooker power rating - a lower wattage one is slower to come to the boil, so actually  uses slightly more energy as it looses heat to the environment for a longer time. 

It takes approx 313 kJ to raise the temperature of one liter of water from 25°C to 100°C, which is 0.087 kWh. 

1kWH would be enough electricity to cook about 3kg of dry rice (in batches) in a rice cooker . . .

I doubt is worth worrying about the cost to run the rice cooker for one person eating the rice.

However if your tenant has an electric room heater, that can run at full power for hours at a time, and many will have power ratings in excess of 1kW.

[shivajikobardan]

They're 4 of them. I wonder how much servings does 1 kg rice gives to an average adult.

[Ian.M]

That depends on the serving size which in turn depends on whether or not the adult works at a desk or does heavy manual labor, and what proportion of their diet is rice.  100g of cooked rice is 10% of the recommended daily carbohydrate intake for a desk-worker assuming a 2000 calorie a day diet.   The manual laborer will need up to twice the calories, and as rice is relatively cheap may eat a higher proportion of rice.   Cooked rice is typically three times heavier due to its water content than the dry rice it started as.

[nightfire]

A bit late to the party, but depending on the dish, I find approx. 100g-125g of Basmati rice my personal best size. for dishes like fried rice it should be a bit more, for dishes with rice as a side order a bit less.