Well This all depends on who is holding the knife..........but as a rough guide, caterers normally cut a fruit cake to be 2.5cm/1in square and sponge cake 5x2.5cm/2x1in. Sponge Cakes Fruit Cakes Cake Size No of Portions No of Portions Round Square 10cm/4in 6 12 13cm/5in 10cm/4in 8 16 15cm/6in 13cm/5in 12 24 18cm/7in 15cm/6in 17 34 20cm/8in 18cm/7in 23 46 23cm/9in 20cm/8in 29 58 23.5cm/10in 23cm/9in 35 70 30cm/12in 28cm/11in 50 100
If you are looking at this with reference to a wedding cake the size will depend on the number of guests at your reception, the size of the slices you’ll serve and whether or not you are keeping the top tier for your first wedding anniversary or christening. If you are serving your cake as a dessert, the slices will need to be bigger than if just served with coffee.
