I have a request for a full sheet cake due on sunday. The cake will be a simple design with shell border, roses and writing. What I am wanting to know is How many will a full sheet cake feed, how big the slices need to be cut to feed that many people. The other question is what would you charge? Also, how do you make a half chocolate/half white cake? Thanks so much ladies for your help!

Let's do math!

GET BACK HERE -- no running away screaming!

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start with...

well, just how piggy do the guests want to be?

ignore the teenage boys who will ask for one whole cake each!

so...

do you want 2x2 pieces of single 2in layer? (that would 8 cubic inches of cake -- a fair amount excpet for the those teen boys -- have baseball bat handy to beat them off)

or do you want 1x2 of a 4 inch double layer (well look at that -- it's also 8 cubic inches)

or maybe you want 2x2 of a 4 in double layer (hoo boy -- that's 16 cubic inches of cake -- the teen boys are still complaining TOO small!)

ok...3x3 of single layer (18 cubic inches)

or 3x3 of double layer (36 cubic inches -- teen boy's call this one bite!)

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in any event (including teen boys trying to run off w/ cake -- use baseball bat!)

it all comes down to....

pick a size of serving...

pick a size of sheet cake (rectangle)

then divide size of cake by size of serving to get number of servings.

so.....

if you start with a 9x13 cake and 3x3 slices...

9 / 3 = 3
13 / 3 = 4 and some "crumbs"
3 x 4 = 12 servings.

but you're on the never ending diet so you go with 2x2 (hey this is cake -- I'm not going to starve ya know!)
with that we get
9 / 2 = 4.5
13 / 2 = 6.5
forget the .5 (that's the cake cutter's cutting fee!)
4 x 6 = 24 --- or double the servings of 3x3 pieces.

ok the doctor called and yelled at you.
down to 1.5 x 2 we go.
9 / 1.5 = 6
13 / 2 = 6.5
give the ".5" to the dog (that is until the vet puts him on a diet too!)
6 x 6 = 36! a 50% increase in servings over 2x2 and 3 times the amount of 3x3

all from one 9x13 cake.

it's all in how big you cut those servings.

works the same for any size rectangle or square cake.

to wit:

11x15 --

3x3 serving
11 / 3 = 3 (with a big strip for the dog)
15 / 3 = 5
3 x 5 = 15

2x2 serving
11 / 2 = 5 (with a smaller strip for Killer)
15 / 2 = 7 (and a strip for Fifi too)
5 x 7 = 35

1.5x2 serving
11 / 2 = 5 (Killer is fighting Fifi for the strip -- Fifi wins!)
15 / 1.5 = 10
5 x 10 = 50

and if by a full sheet you mean 18 x 24...

well back to dividin' and multiplin' we go.

so 2 x 2
18 / 2 = 9
24 / 2 = 12
9 x 12 = 108

etc., etc., etc.

now if you'll excuse me, I have some teens to chase down ....

COME BACK HERE WITH THAT CAKE!

Doug nailed the serving sizes so I won't touch that

On the half white half chocolate. You could do a white half sheet and a chocolate half sheet. I would try to stay away from the term full, half, quarter sheet because everyone's sizes are different. I go by size 8x12, 9x13, 11x15, 12x18. Find out how many servings they need and figure on the 2x2 pieces (if it's for a party) then bake the cake closest to those servings. You could do 2 9x13's one white and one chocolate. Put them next to each other on the board and ice and decorate as one cake.

oh and on charging...

by the serving.

so set a rate -- say $2 a serving.

then if you do the full size at 108 servings....

it's (groan -- more math!)

108 X $2 = $216