# How do I calculate the carbon footprint of an extension board?

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

Weigh the plastic body, brass contacts and copper cable per board and multiply by supplier figures. Add moulding, assembly and testing electricity, divide by boards passed, and report by number of sockets and cable length.

## Materials

- Polycarbonate or PP body.
- Brass sockets and contacts.
- Copper cable and plug.

## Process

- Injection moulding if done in-house.
- Assembly and screwing.
- High voltage testing and packing.

## Per piece

Report per board with socket count and cable length, since the cable is often the heaviest metal part.

## Worked example: extension board unit per piece (one month)

- Electricity: 20,000 kWh x 0.710 = 14,200 kg CO2
- Boards passed: 100,000
- Plant total: 14,200 / 100,000 = 0.142 kg CO2 per piece
- Add plastic, brass and cable 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)
- [Electric switch footprint](https://senseible.earth/answers/electric-switch-carbon-footprint-per-unit)
- [Copper cable footprint](https://senseible.earth/answers/copper-cable-carbon-footprint-per-km)
- [Brass component footprint](https://senseible.earth/answers/brass-component-carbon-footprint-per-kg)
- [Automobile industry](https://senseible.earth/industries/automobile)

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.