My sister asked me to make her babyshower cake. She wants a 2 tier for 45-50 people. I am thinking in making a doble layer 10 & 8" cake. Is this enough?????????
Does the meaurements of the cake slices varies by event? I have read that for wedding cakes there is certain measurements that would feed certain amount of people.
I am totally confused, I amnot sure what pan size I should use

HELP ME PLEASE!!!!!

According to Wilton party servings chart, an 8" serves 20, and a 10" serves 28 (this is for filled cakes either 3" or 4" in height). So an 8"/10" cake should give you 48 servings. Hope that helps!

Industry standard servings are 1"x2"x4" or 2"x2"x2" (8 cu. in. slices). Here's the chart:
http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm

If they want larger servings, they can pay for a larger cake.

Here's Metria's cake calculator, if you want to type in your own serving sizes:
http://shinymetalobjects.net/cake/calculator/cake_calculator_byVolume.cgi

You stated it is for your sister's baby shower - so "industry standard" and "if they want more, they can pay for it" may not be considerations. But, what may be is: what other food(s) will be served? For instance, if it is held around a mealtime, will a full meal be served? If so, industry standard, small slices will be enough. If it is mid-afternoon, and just cake and tea/coffee will be served, then you might want to go up in size for your tiers. Just a thought.

Thanks alot for all of your answers!