To measure the circumference of the dolls head, begin at the middle of the forehead at the hairline. Go under the top of the ears - don't measure over the ears - and to the back of the head at the hairline. Then work your way around the other side under the top of the ears and back to the starting point on the forehead.

Think of the wig as a bowl setting on top of the head. Measure in a straight line and don't measure on top of existing hair unless you plan to put the wig over the old hair. For example, if the measurement is 12 inches, you need a wig size that has 12 in it, like an 11-12 or 12-13. If the measurement is12.5 inches you would probably need the 12-13 size. Hope this helps.