So, we are dealing with vintage clothing and while sizes are pretty much standardised there are difference from brand to brand, here is our interpretation. To get a garment to fit perfectly we would suggest you measure an item of clothing you already own that fits how you want the new garment to fit.
Width / Shoulder width : From the top of the sleeve to the same point on the other side across the shoulders.
Chest / Bust: From pit to pit then doubled e.g 21" becomes 42"
Outer sleeve : From shoulder to cuff
Inner Sleeve : From pit to cuff
Body length : From base of the collar to hem
Leg length : From the base of the crotch to the leg opening
Dress / Skirt length : From the waist to the hem
Playsuit legth : From the base of the collar to the leg opening
Waist : Measured flat then doubled to get a waist size e.g 14" becomes 28"
Hips : Measured at the fullest part beneath the waist
Womens size conversions
Mens size conversions