APPROXIMATE PORTION GUIDE

                                            Fruit Cake                                 Sponge
   Single Tier:                Round      Square                  Round       Square
    5" (13cm)                               14               18                                  8                     10
     6" (15cm)                               22               28                                12                    18
    7" (18cm)                                30               40                                18                    24
    8" (20cm)                                40               54                                26                    32
    9" (23cm)                                54               70                                32                    40
   10"(25cm)                                68               90                                38                    50
   11"(27.5cm)                             86              112                               46                    60
   12"(30cm)                              100              134                               55                     72

   Two Tier:            
  15cm(6")+23cm(9")                      76                 82                                44                    58
   20cm(8")+25cm(10")                   108                 144                                    64                       82
   23cm(9")+30cm(12")                   154                 204                                    88                      112

    Three Tier:
15cm(6")+20cm(8")+25cm(10")    130                170                                    76                     100
15cm(6")+23cm(9")+30cm(12")    176                232                                   100                      130
20cm(8")+25cm(10")+30cm(12")  208                278                                   120                     154
  
This chart is intended to give you a rough idea of how many cake portions can be obtained from a cake -  Please note that these can only be guidelines.  To achieve the portions above the cake must be cut as a grid, regardless of its shape, to gain maximum portions - serving size: 2" x 1".  If cut like a 'pizza' portions will be lost. 
​There is a difference in sponge and fruit cake portioning - fruit cake is finger size slices intended as a gesture for your guests - serving size: 1" x 1".