ISO 8559-2:2017 specifies primary and secondary dimensions for specified types of garments to be used in combination with ISO 8559‑1 (anthropometric definitions for body measurement).

The primary aim of this document is to establish a size designation system that can be used by manufacturers and retailers to indicate to consumers (in a simple, direct and meaningful manner) the body dimensions of the person that the garment is intended to fit. Provided that the size of the person's body (as indicated by the specified dimensions) has been determined in accordance with ISO 8559‑1, this designation system will facilitate the choice of garments that fit. This information can be indicated by labelling, etc.

The size designation system is based on body measurements, not garment measurements. The choice of garment measurements is normally determined by the designer and the manufacturers who make appropriate allowances to accommodate the type and position of wear, style, cut and fashion elements of the garment.