# How do I calculate the carbon footprint of a backpack or school bag?

Canonical: https://senseible.earth/answers/backpack-carbon-footprint-per-piece

Weigh each material in the bag: polyester or nylon fabric, foam, webbing, zips and buckles. Multiply each by its supplier's per-kg figure, add cutting, stitching and packing energy, then divide the unit's electricity by bags passed.

## Materials

- Coated polyester or nylon fabric by weight, including cutting waste.
- Foam padding, mesh, webbing and binding tape.
- Zips, sliders, buckles and plastic stiffeners.

## Making

- Cutting presses, sewing and bar-tack machines.
- Printing or heat transfer of logos.
- Poly bags, hang tags and cartons.

## Per piece

Report per bag by model; the material list usually explains most of the difference between models.

## Worked example: bag unit per piece (one month)

- Electricity: 18,000 kWh x 0.710 = 12,780 kg CO2
- Bags passed: 30,000
- Plant total: 12,780 / 30,000 = 0.426 kg CO2 per bag
- Add fabric, foam, zips and buckles 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)
- [Leather bag footprint per piece](https://senseible.earth/answers/leather-bag-carbon-footprint-per-piece)
- [Non-woven bag footprint per kg](https://senseible.earth/answers/non-woven-bag-carbon-footprint-per-kg)

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.