We measure all garments lying flat, unstretched. Double our flat measurements to see if it will work with your measurements.
The shoulder measurement is just the shoulder seam (across both shoulders).
The bust measurement is armpit to armpit.
The waist measurement is the high waist, unless otherwise specified.
The length for the jeans and pants is the inseam.
The length for the tops and dresses is taken from the highest point of the shoulder.
The length for the shorts and skirts is taken from the top of the waist.
You'll notice each listing has a "Tag size." The size on the tag of a vintage garment might be extremely different from today's sizing standards. Also, things might shrink or stretch over time. While it's nice to know what the size of the garment used to be, you should only rely on the measurements given.