# How do I calculate the carbon footprint of a pair of socks?

Canonical: https://senseible.earth/answers/socks-carbon-footprint-per-pair

Weigh the yarn in a pair, including knitting waste, and multiply by your spinner's per-kg figure. Add knitting, toe linking, dyeing or washing, boarding with steam, labels and packing, then divide the unit's energy by pairs passed.

## Yarn

- Cotton, polyester, nylon and elastane by weight per pair.
- Ask the spinner for a per-kg yarn figure; blends differ.
- Knitting waste and rejected pairs.

## Making

- Circular sock knitting machines and toe linking.
- Dyeing or washing, and boarding on heated forms.
- Pairing, labels, header cards and cartons.

## Per pair

Report per pair by size and style, since an ankle sock and a knee-length sock carry very different yarn weights.

## Worked example: sock unit per pair (one month)

- Electricity: 24,000 kWh x 0.710 = 17,040 kg CO2
- PNG: 2,000 SCM x 2.05 = 4,100 kg CO2
- Pairs passed: 300,000
- Plant total: 21,140 / 300,000 = 0.0705 kg CO2 per pair
- Add yarn per pair for the full figure

Inputs are illustrative; use your own bills and production records.

## What Senseible does here

Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.

- [Product carbon footprint calculator](https://senseible.earth/calculators/product-carbon-footprint)
- [Knitted fabric footprint per kg](https://senseible.earth/answers/knitted-fabric-carbon-footprint-per-kg)
- [Spinning mill footprint per kg of yarn](https://senseible.earth/answers/spinning-mill-carbon-footprint-per-kg-yarn)
- [Textile industry](https://senseible.earth/industries/textile)

Sources: [GHG Protocol Product Standard](https://ghgprotocol.org/standards), [ISO 14067:2018, Carbon footprint of products (iso.org)](https://www.iso.org), [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA CO2 Baseline Database, version 21.0](https://cea.nic.in/cdm-co2-baseline-database/?lang=en)

Last reviewed 2026-10-20.