Most What Katie Did lingerie garments are cut for a Vintage Figure, that is a figure with the hip measurement being 8 to 10 inches bigger than the waist. If you have a Modern Figure (waist less than 6 inches smaller than your hips -and for measuring hips we measure the widest part) it is advisable to go down one size in certain garments.
What Katie Did lingerie dress sizes are based on waist sizes of: Size 8 - 23" waist, Size 10 - 25" waist, Size 12 - 27" waist, Size 14 - 29" waist, Size 16 - 31" waist, Size 18 - 33" waist.
Fitting notes are included in garment descriptions where needed. No notes mean there's nothing to worry about and the garment is suitable for all