It's really hard to tell, but would anyone be able to guess the size of these tiers, or at least the size difference between the tiers?! 

I have to make a 5 tier version next month and not sure I'll be able to get the largest size in my oven! 

Many help is really appreciated

Cara

i'd say the difference is from bottom to top 3", 2", 3' -- the bottom tier is three inches bigger than the next tier, then that one is 2" bigger, then the next one is 3" bigger than top tier --

for example a 12 x 9 x 7 x 4

for a 5 tier you could do a 14 x 12 x 9 x 7 x 4 -- so that's a 2', 3', 2', 3' difference between tiers unless you wanna go with a 3", 2", 3" 2"  difference it'd be ughh,  13 x 10 x 8 x 5 x 3"  kinda small top tier margaret braun does it somehow -- but a better thing would be 14 x 11 x 9 x 6 x 4

but i mean this is a negligible nearly non-existent difference to the 99.9% of brides  -- usually cakes like this are produced per serving -- if a cake is designed to match a silhouette it's usually a more dramatic design kwim

How many servings does the cake you're making need to be? That will determine the tier sizes.

so will a 14 fit in your oven? you could always bake eight 7" cakes and put them all together four on the bottom four on top to make the second layer (i mean torte if you want of course)  and sandwich them all together with icing

The bride likes the cake, so isn't too bothered about the portions. It's more about the look of the cake. 

I will use dummies if I end up with more servings than needed!

Those piped tiers seem deeper than the others too... 

She only wants 100 portions, but a 5 tier cake...

so a 4/7/9/12 would give me 100ish portions?! Then I could do a 14 inch dummy.

fantastic. Thanks for your help!!

cool -- you're welcome -- love to see a picture -- no pressure -- best to you