Tip: When choosing a corset please focus mostly on your bust size and overall size, because all Lena-style corsets are either adjustable on the back or materials were used are expandable.
Lingerie sizing will vary depending on your body shape. So it is important to fit for largest measurement according to the garment your looking to fit. If it is for a brief, you can safely ignore the bust size and conversely if fitting for a camisole, you can ignore the waist and hip measurements. For nighties it is best to use all three measurements and fit appropriately.