# How do I calculate the carbon footprint of an alloy wheel?

Canonical: https://senseible.earth/answers/alloy-wheel-carbon-footprint-per-wheel

Most of an alloy wheel is aluminium: multiply the cast weight, including gates and swarf, by the alloy supplier's figure. Add melting, low pressure casting, heat treatment, machining and painting energy, then divide by wheels passed.

## Material

- Aluminium alloy by cast weight.
- Swarf and rejects remelted.
- Paint and lacquer.

## Process

- Melting furnaces.
- Low pressure die casting and heat treatment.
- Machining, painting and testing.

## Per wheel

Report per wheel by size and finished weight. Recycled alloy lowers the figure.

## Worked example: alloy wheel unit per wheel (one month)

- Electricity: 150,000 kWh x 0.710 = 106,500 kg CO2
- PNG: 50,000 SCM x 2.05 = 102,500 kg CO2
- Wheels produced: 30,000
- Plant total: 209,000 / 30,000 = 6.967 kg CO2 per wheel
- Add aluminium alloy 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)
- [Aluminium die casting footprint](https://senseible.earth/answers/aluminium-die-casting-carbon-footprint-per-kg)
- [Tyre footprint](https://senseible.earth/answers/tyre-carbon-footprint-per-unit)
- [Aluminium industry](https://senseible.earth/industries/aluminium)

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.