Environmental footprint calculators

Footprint calculators

An environmental footprint calculator estimates the environmental impact of specific activities, such as transport and energy use, food consumption, and production and use of products.

This page was developed through the Footprint Evaluation Initiative. Thanks to the Footprint Evaluation Community members, Paul Jorgensen, Ian Goldman and Jen Noris, for helpful feedback on the initial draft of this page.

Many of these calculators focus on individual or household consumption and waste production. Others focus on organisational footprints, especially in meeting commitments to zero carbon and ESG (Environmental, Social, and Governance) goals.

Footprint calculators for products often take a life cycle stages approach, considering impacts from sourcing raw materials and production, through use and end-of-life, including potential impacts from disposal.

The environmental impacts considered by a footprint calculator may be broad or specific. For example, individual calculators for water usage, stormwater, nitrogen production, biodiversity, and greenhouse gas emissions exist. The ecological footprint calculator covers a range of ecological assets that a given population or product requires to produce the natural resources it consumes and to absorb its waste, especially carbon emissions.

Environmental footprint calculators work by synthesising available evidence about the likely impacts of different activities and then providing an interactive tool to estimate the scale of these impacts for a particular activity level. For example, when estimating greenhouse gas production through private motor vehicle use, a calculator might provide an opportunity to adjust the number of kilometres travelled per year and the engine size and type.

Since most of the calculators are intended for use by individual households or companies, they can be useful for informing and motivating individuals or organisations to make changes to reduce their negative environmental impacts. However, their use in evaluations of programs and policies has not been as well documented. There are two main caveats to using footprint calculators in evaluations of programs, policies, and projects.

Firstly it is important to consider whether a particular type of impact is likely to be material and, therefore, important to include. For example, a project might not have significant greenhouse gas emissions, so calculating these would be of little benefit to the overall evaluation and would risk diverting evaluation effort and user attention away from more important impacts. This fits with one of the principles underlying footprint evaluation – 'focus on the big issues'.

To identify whether a type of impact is likely to be important, it might be possible to undertake a materiality assessment - consulting with internal and external stakeholders to identify types of impacts with the potential to be significant. It might be possible to draw on guidance for particular sectors to identify important issues. For example, the GRI (Global Reporting Initiative) has produced sector standards, which identify the topics that are likely to be material for organisations in particular sectors and reporting standards for particular topics. The CEDRIG rapid assessment tool (PDF, 392KB) provides a list of potential impacts to consider and a process to engage expert advice to review them.

The second issue concerns the credibility and relevance of a particular footprint calculator for an evaluation. Calculators vary in terms of the factors they cover, the assumptions and evidence they are based on, and the ability to provide more specific information. Many calculators have been developed in specific countries (especially the USA and UK) and might have limited validity if used in countries where the underlying assumptions don't hold. There is an ISO Standard 14067: 2018 for the quantification of the carbon footprint of products which sets out principles, requirements, and guidelines.

Reviewers: Thanks to Paul Jorgensen, Ian Goldman and Jen Noris for helpful feedback on the initial draft of this page.

Advice for choosing this method

  • You might need to use a number of calculators to cover all potential environmental impacts
  • Before deciding to use a footprint calculator, get some advice about whether this particular impact has the potential to be significant, and choose a calculator which covers these types of impact
  • Choose a calculator which is transparent about its data sources and assumptions and where these are relevant to your location and situation
  • Choose a calculator which provides significant opportunities to provide data to finetune the estimate – for example, the type of car driven or the type of electricity used.

Advice for using this method

  • These calculators can be particularly important in providing evidence-informed estimates early on in implementation rather than waiting to track actual impacts. They can be used to compare the likely effects of different options and to estimate the estimated effect of changes in activities. In this way, they can be useful in informing change and reductions in negative environmental impacts.
  • The calculators can be useful in raising awareness of likely impacts as long as they cover all relevant activities
  • Make sure to also explore potential impacts that are not considered by the calculator – for example, pollution from waste disposal as well as impacts on resource usage.


Specific environmental footprint calculators


Other related resources

This page was developed through the Footprint Evaluation Initiative. Reviewers: Thanks to the Footprint Evaluation Community members, Paul Jorgensen, Ian Goldman and Jen Noris, for helpful feedback on the initial draft of this page.

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