# How do I calculate the carbon footprint of barbed wire per kg?

Canonical: https://senseible.earth/answers/barbed-wire-carbon-footprint-per-kg

Multiply the galvanised wire per kg by the supplier's figure, or add your own drawing and galvanising energy and zinc. Add the barbing machines and packing, then divide the unit's energy by kg dispatched.

## Material

- Galvanised wire, or wire rod plus zinc if galvanised in-house.
- Coil ties.
- Packing.

## Process

- Wire drawing.
- Galvanising bath, if done in-house.
- Barbing and coiling machines.

## Per kg

Report per kg, then per roll by roll weight.

## Worked example: barbed wire unit per kg (one month)

- Electricity: 15,000 kWh x 0.710 = 10,650 kg CO2
- PNG: 3,000 SCM x 2.05 = 6,150 kg CO2
- Kg dispatched: 150,000
- Plant total: 16,800 / 150,000 = 0.112 kg CO2 per kg
- Add wire and zinc 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)
- [Hot-dip galvanizing footprint](https://senseible.earth/answers/hot-dip-galvanizing-carbon-footprint-per-tonne)
- [Steel wire drawing footprint](https://senseible.earth/answers/steel-wire-drawing-carbon-footprint-per-tonne)
- [Steel industry](https://senseible.earth/industries/steel)

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.