Published on october 1, 2022

The Methodology Behind our Eco Stats 

written by Team thredUP


thredUP is committed to slowing down fashion waste and reducing our impact on our planet by extending the life of clothing. Every time you clean out your closet, you’re keeping clothing in use and out of landfill. Every time you buy a secondhand clothing item instead of new, you’re displacing the need for new clothing production and reducing carbon, waste, and water footprints. Well done, thrifters! The positive impact of choosing used over new is real. Let us explain.

We partnered with independent research firm Green Story Inc. to help us calculate the impact of buying a secondhand clothing item as compared to buying a new one. You can find this info on the product detail page of most of our women’s clothing items on our site. This way you can feel extra great about refreshing your wardrobe at thredUP versus splurging on brand new items.

Savings are estimated based on the 2022 LCA study conducted by Green Story Inc., measuring the impact a new and secondhand garment has in terms of carbon dioxide (CO2) emitted, and energy and water consumed each time the consumer wears it. The numbers refer to the average fabric composition and weight of an item within a category and are not specific to a particular item.

The 2022 LCA was conducted for 15 categories. Tops, dresses, tees, sweaters, jeans, pants, skirts, outerwear, shorts, active pants, active tops, sweatshirts, jumpsuits, swim, and blazers.

The new garment footprint accounts for raw material extraction, yarn production, fabric production (weaving or knitting), dyeing, cutting and sewing, transportation from the country of origin to the distribution center, use of garments (washing), and disposal (landfill, recycling, incineration). The secondhand garment will have footprints from the transportation from the seller to thredUP, cleaning, warehousing, transportation to/from thredUP to the buyer, use of garments (washing), and disposal (landfill, recycling, incineration).

Not every secondhand garment purchased completely replaces a new purchase. This only happens 72% of the time. The other 28% of the time a new garment is purchased. So the actual impact of the secondhand garment also includes the impacts of garments that are not displaced.

Findings were supported by millions of thredUP’s historical data points on clothing categories and composition (hello, millions of items processed!). For more information, please see our Resale Report and our Fashion Footprint Calculator.