How to Measure Your Body: Shoulder Width
This measurement will require a partner. If you don’t have a partner, measure a shirt directly. Either way, it’s helpful to refer to a shirt that fits well in the shoulders. Start the end of the tape on the outside edge of the shoulder where you want the yoke of the shirt to start. This is where the horizontal part of the shoulder meets the vertical part of the arm. Measure up over the curve of the shoulders and to outside edge of the other shoulder.