HOW WE CALCULATE IMPACT DATA

Taking Back an Item to Recirculate it Mitigates
60% of the Impact of Making a New One

When a brand takes back a used item instead of letting it go to landfill, and that item finds a second life through resale, it stands in for – or displaces – a new item that doesn’t have to be manufactured.

This framework comes from the science of Life Cycle Assessment (LCA), which evaluates a product’s environmental footprint throughout its lifespan, from raw material extraction, manufacturing to distribution, use, and final disposal. For a garment, this involves the environmental impacts from harvesting raw materials, spinning yarn, dyeing fabric, cutting and assembling the finished piece, wearing and caring for it, to disposing of it when it’s no longer desired.

In LCA methodology, the net environmental saving of recirculating clothing depends on a critical factor called the “displacement rate”. It measures how many new garments are avoided when consumers buy preloved items. A 100% displacement rate means that the item fully substitutes a new one. However, the rates are often lower than 100% in reality.¹

To establish a reliable benchmark, we looked at a wide range of academic studies, industry reports, and resale data. The most robust figures we found come from the global environmental action organisation WRAP. Their Displacement Rates Untangled report identifies a 64.6% displacement rate for UK peer-to-peer apparel resale, which means that for every 5 preloved items purchased, roughly 3 of them displace a new purchase². This standardised method was developed and tested across the sector, including by major resale platforms eBay, Vestiaire Collective and Depop.

For our impact modelling, we apply a discounted displacement rate of 60% (0.6) to account for differences between peer-to-peer resale and our managed take-back model, ensuring our calculations remain conservative and realistic while we collect our own platform-specific displacement data.

Our Base Data

For new clothing, we apply recognised global textile impact benchmarks per kilogram (kg) of clothing to establish the baseline footprint of manufacturing a brand-new garment, and assign a category weight to the item to determine its weight.

Base Impact Benchmarks (Per 1 kg of New Clothing)

Carbon Footprint: 25 kg of carbon dioxide equivalent (CO2e).

Water Footprint: 5,000 litres of water

Supply Chain Waste: 1.1 kg of waste generated

Category Weight Assumptions

  • Lightweight (Tops, Shirts, Blouses): 200 grams (0.2 kg)
  • Medium-weight (Dresses, Jumpsuits, Knitwear, Pants, Summer Jackets): 400 grams (0.4 kg)
  • Heavy-weight (Denim Jeans, Jackets, Heavy Material Skirts): 600 grams (0.6 kg)
  • Extra-heavy (Heavy Jackets, Coats, Outerwear): 1,000 grams (1.0 kg)

Our Formula

Putting it all together, let’s now calculate the environmental impact of buying a preloved dress that weighs roughly 400 grams compared to purchasing new. Using the formula,

Displacement Rate (0.6) × Impact of 1 kg of New Clothing × Item’s Category Weight (0.4)

  • 6.0 kg of CO2e: Equivalent to driving an average passenger car about 50 km – the distance from the east to the west of Singapore.
  • 1,200 litres of water saved: Enough drinking water for one person for over 1.6 years.
  • 0.26 kg of waste diverted from landfill: Equivalent to 32% of the 0.83 kg waste produced daily per person in Singapore. For context, the national target is to reduce daily waste sent to the Semakau Landfill by 30% by 2030 to sustain its longevity.

DISCLOSURES

There are recognised limitations in the generalised environmental impact model we use. We are transparent that our figures represent conservative, peer-reviewed benchmarks rather than an individualised supply chain audit of every item in our store. Where uncertainty exists, we have purposefully chosen the lower end of published ranges, or applied a conservative simplification, and disclosed it here.

  • Fibre mix: Fashion brands use a variety of materials, many of which are blended. However, verified environmental impact data does not exist for all fibres and material compositions. We are limited by data availability, and our method is based on standardising material mix across categories. These assumptions may not reflect the actual material composition of an individual garment, or of a particular brand.
  • Displacement Rate: WRAP notes that its published displacement rate is weighted for the UK market. Actual displacement rates in Singapore and the wider Asian market may differ.
  • Weight: Our category weights are standardised averages. Individual garments within a category may weigh more or less than the assumed baseline figure.
  • Resale Process Impact: Taking back garments and processing them for resale generates its own environmental footprint, which will offset a portion of the net gains.
  • Scope of impact Categories: Our model quantifies carbon, water, and waste impact – the three categories for which credible, published data is most available. It does not account for other recognised environmental impacts of textile production and use, including microplastic fibre shedding, land use, and chemical pollution from material cultivation and processing.

That said, findings across all major studies including our calculation confirm the core directional message: choosing preloved clothing over new results in net environmental savings in carbon, water, and waste footprint.

REFERENCES

LCA methodology and product displacement

Carbon footprint data

Water footprint data

Fabric waste data

Equivalency conversion factors

CITATION GUIDELINES

This methodology – including the calculation framework, applicable displacement rates, and base impact figures – is original work developed by Lucerna Impact, derived from a verified set of academic and industry sources.

You’re welcome to reference it in your own published content. Please cite as: Environmental Impact Methodology, Lucerna Impact, www.lucernaimpact.com/impact-data. Accessed [insert today’s date]. If you’re referencing a specific figure or calculation (for example, the cotton water footprint or displacement rate), please cite both Lucerna Impact and the original source as listed on this page.

What’s not permitted: reproducing or closely paraphrasing this methodology on another site, presenting it as your own work, or using it as the basis for a competing calculation tool or service. Please refer to our Terms of Service for further details.

Lucerna Impact maintains this page as a working reference and updates it as sources and figures are revised. We’re not responsible for how third parties apply or interpret these figures in their own claims.

For questions about licensing or attribution, please contact us at research@lucernaimpact.com

Last updated: 22 June 2026