We only need 2 measurements of OG(head Circumference) and GSH (depth of the cap), if you do not have a centimeter tape, you can do with a lace or thread for knitting, which is then re - measured with a ruler, but I advise you to buy a tape-it is very convenient.
Formulae:
The height of the patterns =(TS+8)/2
Pattern width =(OG-decrease)/4 ,
decrease - for ribana and kashkorse 9cm, for acrylic 5cm, for footer 3-4cm