Average sustainability index

We have chosen to work with an overall sustainability index for all garments, as opposed to a more specific, item-by-item approach. There is no reason to buy T-shirts differently from trousers

We decided to work with 2 sets of data: the average number of wears per garment, taken from the PEFCR, European methodologies for the textile industry, and also the number of garments actually purchased per year. Crossed with the number of times in the year that the garment can be worn and the number of 'active' garments in the wardrobe, we obtain a real number of wears.

For each garment, we calculated an average durability index according to the formula: 'durability index = actual number of wears / average number of wears', bearing in mind that the value of this index is restricted to between 0.67 and 1.45. This gives an average figure of 0.91 for average purchases.