1. The circumference around (1 inch above) the base of the neck

Measure along the natural contour of the neck, holding the tape measure comfortably against the skin.

尺码中第二个参数是袖长（Sleeve Length）：这个袖长并不是我们传统说的从肩膀到袖口的长度，而是从脖子下端中央到肩膀外端，然后经手肘外端直到腕部衬衫袖子位置的长度。 A. Base of neck (backside, center) B. Outside tip of shoulder C. Outside bend of elbow D. Wrist or the point at which you prefer the cuff to end 1. Rest your hand on the side of your hip, with elbow bent. 2. Measure as shown in the illustration: - Start at (A) the backside base of the neck, - past (B) the shoulder, - around (C) the elbow, - to (D) the wrist or point at which you prefer the cuff to end. The path of the tape measure should follow the outside of the arm. (or, look for your 'Dress shirt sleeve length' on the size tag of a dress shirt that fits well.) 版型：一般比较适合国人的是Regular Fit和Slim Fit。Slim Fit比较贴身点，不像Regular Fit比较宽松。那么对于体型在略胖以下的，适合Slim Fit多点，体型在略胖以上的，适合Regular Fit多点。 另外衬衫有个参数叫做胸围，在尺码表里会看到，但是在选择衬衫尺码的时候这个参数并不会出现，请注意比对商品页面的Size Info，以免拿到衬衫之后发觉衬衫很肥。其他常见描述，Machine Wash 可机洗，Non-Iron 免熨烫，Straight cuff 直袖口，Double-cut cuff 双切角袖口。PS2: 附上比较实用的网站，可以查看各种衣服的尺寸如何测量。