We suggest if you have not purchase Tap shoes before you have them professional fitted at Dancewear Nation (Williamstown) or any Bloch store 

Size Chart below 
School Shoe (UK) 
7 - 15.4cm length 
7.5 - 15.6cm length 
8 - 16cm length 
8.5 - 16.4cm length
9 - 16.8cm length
9.5 - 17.2cm length
10 - 17.6cm length
10.5 -18cm length
11- 18.4cm length
11.5 - 18.8cm length
12 - 19.2cm length
12.5 - 19.6cm length
13 - 20cm length
13.5 - 20.4cm length
1 - 20.8cm length