Companies representing more than a third of UK clothing sales have signed the Sustainable Clothing Action Plan (SCAP) 2020 Commitment, a scheme that will see them work together to reduce the environmental footprint of clothing.

The programme will see retailers, brands and suppliers measure the carbon, water and waste footprint across the supply chain, from supply, through to customer use, to end of life.

Arcadia, Asos, the British Retail Consortium (BRC), John Lewis, Marks and Spencer, Next, Sainsbury's and Tesco are among the 22 companies to have signed the commitment.

UK government's Waste & Resources Action Programme (WRAP) has developed a spreadsheet-based footprint calculator, which will enable companies to quantify and report the total global impacts of the clothes they make, sell and recover, in a consistent way.

The baseline data for 2012 will enable the signatories to agree targets for carbon, water and waste savings, to be delivered by 2020, but also to identify ‘next steps'.

WRAP chief executive Liz Goodwin said: "We know that overall, clothing contributes around 5% of the carbon footprint and between 6-8% of the water footprint of all the UK's goods and services. It also accounts for more than 1m tonnes of wasted materials, making it the most significant category for consumption impacts after food and drink, housing and transport.

"SCAP is an opportunity for all players in the sector to work together to reduce these impacts, making individual changes for a common good. The launch of the calculator represents an important step forward."

Member retailers will commit to using lower-impact fibres, extending the active life of clothing, recovering material that currently goes into the bin, and providing more information for consumers on environmental impact.

Part of the scheme will also include recording the weight of clothing collected or handled and its end destination - reuse in the UK or overseas, recycling, incineration and landfill.