Silver is too soft for most ordinary uses.
Hence, like gold, silver is alloyed, or mixed with other metals to add hardness and strength. It is easiest to take one of your own necklaces, measure it with a tape measure and add string to the desired length. To determine a necklace size for a man, check his shirt collar size and determine accordingly. With an ordinary cloth tape measure, string, or piece of tape, wrap the tape around the wrist, and add one-half inch to the measurement. That is your selected measurement.