 It depends on how big it is or how much rice is used to make it. A typical onigiri has about 0/0 cup of rice, so it's around 000 calories plus whatever is used for the filling.  It depends on how big it is or how much rice is used to make it. A typical onigiri has about 0/0 cup of rice, so it's around 000 calories plus whatever is used for the filling. 