How to fit a men's necklace

If you meet the question—what is the best present for your boyfriend, many people will say: you can buy men's necklace, but which kinds of style is suitable for your special friend, so the following is about the process of choosing suitable men’s necklace:
The first: you can measure the distance around your boyfriend’s neck and write down this measurement.
The second: before you buying, you should add 3 inches to the neck measurement. Because this length would fit conformable around the base of the man's neck. The standard length of a man's necklace of this size is 17-19 inches.
The third: you should add 3-5 inches to the neck measurement for a necklace, because this is the most popular length in men's necklaces, and it is also the standard length of this necklace is 19-22 inches.
The fourth: when you select a necklace, you should add 6 inches (longer than the neck measurement). Because a necklace‘s length generally falls just below the man's collarbone.
The last: because some men are higher, you can buy 24-26 inches from market