The easiest way to measure your neck if you do not have a tape measure is to cut a long strip of paper or 2 pieces of paper taped together making them long. Cut a long skinny 1/2" strip and use it as a tape measure. Put it around your neck up to the length that you think is comfortable. Mark the paper and then take it off and measure where you have it marked. That is your wearable length. When I say a necklace is 15" it is a wearable 15". Occasionally it has a pearl or something on the end that hangs past the clasp. I do not count that as the wearable length. I measure up to it but not including it. Sassy