XXX-Small 14-16cm (5 1/2-6") XX-Small 15-17cm (6-6 1/2") X-Small 16-18cm (6 1/2-7") Small 19-22cm (7-8 1/2") Medium 21-24cm (8-9 1/2") Large 23-27cm (9-10 1/2") X-Large 26-29cm (10-11 1/2") XX-Large 29-32cm (11-12 1/2" )