UK	EU	US	Length (in/cm)	Circumference (in/cm)	Instep (in/cm)
3	35/36	5	8 9/16″ / 21.6cm	8.25″ / 21cm	9″ / 22.9cm
3.5	36	5.5	8.75″ / 22.2cm	8.3″ / 21.1cm	9.1″ / 23.1cm
4	36/37	6	8.875″/ 22.5cm	8.4″ / 21.3cm	9.25″/ 23.5cm
4.5	37	6.5	9″ / 23cm	8.5″ / 21.6cm	9.4″ / 23.9cm
5	37/38	7	9.25″ / 23.5cm	8.75″ / 22.2cm	9.7″ / 24.6cm
5.5	38	7.5	9.375″ / 23.8cm	8.9″ / 22.6cm	9.8″ / 24.9cm
6	38/39	8	9.5″ / 24.1cm	9″ / 22.9cm	9.9″ / 25.1cm
6.5	39	8.5	9.6875″ / 24.6cm	9.2″ / 23.4cm	10.1″ / 25.7cm
7	39/40	9	9.875″ / 25.1cm	9.4″ / 23.8cm	10.3″ / 26.2cm
7.5	40	9.5	10″ / 25.4cm	9.5″ / 24.1cm	10.5″ / 26.7cm
8	40/41	10	10.1875" / 25.9cm	9.7″ / 24.6cm	10.6″ / 26.9cm
8.5	41	10.5	10.375″ / 26.2cm	9.8″ / 24.9cm	10.8″ / 27.4cm
9	41/42	11	10.5″ / 26.7cm	10″ / 25.4cm	11″ / 27.9cm
9.5	42	11.5	10.6875″ / 27.1cm	10.2″ / 25.9cm	11.2″ / 28.4cm
10	42/43	12	10.875″ / 27.6cm	10.3″ / 26.2cm	11.4″ / 29cm

UK	EU	US	Length (in/cm)	Circumference (in/cm)	Instep (in/cm)
5.5	39	6	9.25″ / 23.5cm	9″ / 22.86cm	10″ / 25.4cm
6	39/40	6.5	9.5″ / 24.1cm	9″ / 22.86cm	10″ / 25.4cm
6.5	40	7	9.625″ / 24.4cm	9.2″ / 23.4cm	10.1″ / 25.6cm
7	40/41	7.5	9.75″ / 24.8cm	9.25″ / 23.5cm	10.2″ / 25.9cm
7.5	41	8	9.9375″ / 25.4cm	9.5″ / 24.1cm	10.4″ / 26.4cm
8	41/42	8.5	10.125" / 25.7cm	9.5″ / 24.1cm	10.4″ / 26.4cm
8.5	42	9	10.25″ / 26cm	9.75″ / 24.8cm	10.75″ / 27.3cm
9	42/43	9.5	10.4375″ / 26.7cm	9.9″ / 25.1cm	10.9″ / 27.7cm
9.5	43	10	10.5265″ / 27cm	10″ / 25.4cm	11″ / 27.9cm
10	43/44	10.5	10.75″ / 27.3cm	10.2″ / 25.9cm	11.2″ / 28.4cm
10.5	44	11	10.9375″ / 27.9cm	10.4″ / 26.4cm	11.4″ / 29cm
11	44/45	11.5	11.1625″ / 28.3cm	10.6″ / 26.9cm	11.7″ / 29.7cm
11.5	45	12	11.25″ / 28.6cm	10.7″ / 27.2cm	11.75″ / 29.8cm
12	45/46	12.5	11.5″ / 29.2cm	10.9″ / 27.7cm	12″ / 30.5cm
12.5	46	13	11.5625″ / 29.5cm	11″ / 27.9cm	12″ / 30.5cm
13	46/47	13.5	11.75″ / 30.2cm	11.1″ / 28.2cm	12.2″ / 31cm