A larger foam head, canvas head or wig block will be more accurate and is worth the extra $$$.
If your wig head is too small, you’ll end up cutting the wig too short or making it too tight when you sew in wefts or style an updo. As a quick fix, you can stuff paper under the wig to stretch it in the back. A larger foam head, canvas head or wig block will be more accurate and is worth the extra $$$.