According to our information, the size is based on the circumference of the hand.
It is measured without the thumb, at the widest part of the hand.
Size chart (adults):
6.0 = approx. 15-16 cm
6.5 = approx. 16-17 cm
7.0 = approx. 17-18 cm
7.5 = approx. 18-19 cm
8.0 = approx. 19-20 cm
8.5 = approx. 20-21 cm
9.0 = approx. 21-22 cm
9.5 = approx. 22-23 cm
10.0 = approx. 23-24 cm
10.5 = approx. 24-25 cm
11.0 = approx. 25-26 cm
These are approximate values.
They may vary slightly depending on the fit.