Most of us measure by starting at the hairline on the forehead, then going over the top of the head, down the back to get the length.

The method you use does not really matter as long as you use the same method each time.

Some people measure their hair dry, others measure wet or damp (particularly the curly hairs!)  Again, consistency is the key.

From one curly to another!!!  Measure when your hair is wet,makes you know how  long your hair really is .