I am running an after school class where i am going to teach the kids to do the rosette on top of the cupcake with the 1M tip. Each kid will have 6 cupcakes, there are 22 kids (omg!), so 132 cupcakes. 

I made the traditional wilton buttercream, 1/2 cup crisco, 1/2 cup butter, 4 cups of powdered sugar. I have 8 batches made already.

will that be enough? any other time I've ever done cupcakes in a large scale i've been at my house so i could always whip up extra if needed. I would rather have too much than not enough, of course. 

is there a rule of thumb that 1 batch of frosting covers X number of cupcakes?

AMy recipe for bottercream is double the amount of your and I cover roughly 24 or so cupcakes with my batv h of frosting....so I would say that you will get a dozen out of one of you recipe , so I figure yo u roughly need 11batches. Hope this helps good luck and have fun with the kids

thanks! that's the answer I was NOT hoping for, lol...I am out of crisco so need to go get some. I am trying to get this all done tonight, plus finish baking and plating 3 lbs of cookies for an order tomorrow, so that way if the school I sub at calls me in the morning I can go do that. Clearly I need my head examined!!! lol
 

Hey I am responding because I do cupcake benefit for a lil boy and I will say that I too am trying to find out exactly how much one batch of frosting frost how many cupcakes. I make regular cupcakes and my frosting is 1/2c Crisco, 1/2c butter, 1/2c milk, 1 bag of powder sugar and a teaspoon of vanilla. Now my first year of doing cupcakes I made 1600 cupcakes and thinking about 48 to a batch I made 33 batches. I will say I had WAY TOO MUCH frosting. So I am thinking that one batch is enough for 72 cupcakes. When I was done frosting ALL the cupcakes I had a 5 gallon bucket left of frosting! I see that you can freeze frosting. How long is it good for in the freezer? And how do you defrost if so it doesn't get soupy? Thank you all for your help!