You can adopt the pattern tailored to the different sizes, taking into account the circumference and length of the foot to the heel.
For that it will be necessary to go measuring the foot and testing the stocking as it is knitted.
This pattern is designed for a circumference of 24 cms, length of 25 cms, size 40.
Here I leave some estimative measures according to the size:

1. 26 to 34 Circumference 16 to 20, length of foot 18 to 21 cms
2. 35 to 40 Circumference 21 to 24 cms, standing length 24 to 26 cms
3. 41 to 45 Circumference 24 to 26 cms, foot length 27 to 29 cms