The number of loc extensions depends upon the hair thickness, the diameter of locs, and other factors. You will probably require many locs to get a fuller look if you already have thin hair. On the other hand, if you have thick hair, you can add only a few locs for extra volume and length.  Here is a rough estimate of the number of locs required for normal straight and curly hair: For straight hair: · 40-50 (locs) medium to thick extensions for straight hair · 60-70 (locs) skinny extensions for thin straight hair For Afro Kinky hair: · 40-60 (locs) medium to thick extensions for Kinky Afro hair · 80-120 (locs) skinny extensions for thin Kinky Afro hair