Where is the length measured from for "CB Sleeve Length" shown in the size chart?

Let's look at the numbers first. Wool Button Up Shirts Jacket charcoal has a sleeve length of 28.9 for size M and 30.4 for size L^[1]. Pocket Zip Up Jumper beige is 64.1 for M and 65.6 for L^[2]. Even under the same name of sleeve length, the gap between the numbers is this wide. This means that just looking at the numbers, you cannot tell where the tape measure started.

In the AMOMENTO size chart, there is a separate item called CB Sleeve Length, where CB stands for Center Back Sleeve Length^[3][4]. Since the center back standard measures continuously starting from the center of the back neck, along the shoulder line, and down to the sleeve hem, it results in a value longer by the back and shoulder width than a measurement taken from the shoulder point. This method is commonly used for clothes where it is difficult to pinpoint the shoulder tip, such as drop shoulders where the shoulder line sits down toward the arm, or raglans where the seam runs diagonally from the neck to the armpit.

Therefore, when comparing sleeve lengths, it is safer to check the item name before the numbers. When comparing by measuring clothes you currently wear, the starting points must match for the two numbers to correspond properly. The brand also notes that differences of 1~2cm may occur depending on measurement positions and fabric elasticity, so reading the numbers as an approximate range rather than relying strictly on the single decimal place is closer to reality^[5].