Here are the calories based on the follow quantities:
2 Tablespoons Canola Oil
40 Large or 4 cups Mini Marshmallows
4 cups Rice Krispies
Makes 24 squares
Serving size: 2 squares
Calories per serving: 124
The "original" Rice Krispie Treat" recipe calls for 6 cups, but everyone else on post for RKT that is in the recipe index said they used 4-4-1/2 cups. So, to figure it out.... 1 cup of Rice Krispie Cereal is 100 caloires . So, you can adjust your calories accourdingly.