Carbon footprint calculators – what to ask to help you choose

Knowing the carbon footprint of your farm is becoming increasingly important. Some processors and buyers are already asking for footprints as part of their environmental obligations, and the number is likely to increase. It can show the GHG emissions hotspots in a business and where improvements should be made. Additionally, being able to show positive change in your footprint has the potential to bring extra income in the future, such as through the carbon markets.

There are many carbon footprint calculators out there. The best action is to pick one and stick with it, so that a consistent record of your footprint over time can be made starting with a baseline. It is therefore important to make sure that you pick the right tool for you. Below, we have provided some important questions you should ask when choosing a carbon footprint calculator tool.

These questions determine whether the tool is right for you and your farm.

• Does my buyer/supply chain require a specific tool? 
  • Check if your supply chain specifies a particular tool.
• Does it cover everything my farm produces?
  • Some tools cover all crops and livestock species, while others focus on a specific sector.
• What levels of footprint are provided?
  • Tools may provide footprinting at whole farm, enterprise, production system, or product levels.
• How easy is the data entry process – do I need support?
  • Often you can enter your own data and written guidance is provided. Some tools require more detailed information while others have a simplified option. Some tools also offer to help with the data entry, often for a fee.
• How much does it cost?
  • There are several free options available. These may then have extra features (such as assistance or benchmarking) for a cost.
• Can I make comparisons?
  • This could be ‘what if’ scenarios, comparisons over time, or benchmarking against a group. See if this service is provided – and if it costs extra.
• Does it include carbon sequestration?
  • Some tools also include carbon sequestration, mainly sequestration of soil carbon.

These questions help ensure you have the best data possible – and will be important to those who might want to see the data as proof of your footprint. 

• Do they adhere to a set standard?
  • A calculator should be based on robust science and data. Adherence to a set standard is a quick way to show this. Officially recognised standards for carbon footprinting exist, but not all calculators use them. The main one for the UK is the PAS 2050:2011 standard from the BSI (British Standards Institute). Additionally, the IPCC has set methodology to account for greenhouse gas emissions, and some calculators follow this methodology. This could be either at tier 1 (basic) or tier 2 (intermediate).
• How does it cover methane and nitrous oxide emissions?
  • These are the two main greenhouse gases from agriculture. In order to be comparable with carbon dioxide emissions the amounts are routinely calculated as carbon dioxide equivalents (CO2e) using the global warming potential over 100 years.
    Some tools are introducing dual reporting, using GWP* for methane to better take account of its relatively short-lived nature in the atmosphere.
• Is it regularly updated and improved, using the most up-to-date science based information?
  • A static tool that doesn’t get updated doesn’t just miss out on gaining new features, but also may not reflect the latest scientific data e.g. on emissions factors.
• Does it link to assessments of other environmental impacts?
  • A number of the tools are also linking to water and biodiversity metrics.
• Is the tool independent?
  • Some companies may use their footprinting tool as a door to selling other services, such as carbon trading schemes. Check you are happy with how your data will be used.

These are some popular carbon tools, alphabetically: Agrecalc, Cool Farm Tool, Farm Carbon Toolkit, SolAgro and Trinity Agtech (Sandy)

We will be updating this page with a comparison of these tools later in 2023. In the meantime, several companies have done comparisons of carbon tools already. Some of these are below, though it should be noted that they may not reflect the latest version of each tool, as they are updated and improved regularly.

Greenhouse gas calculators – where to start? – NFUonline

4 popular carbon calculators for farms compared - Farmers Weekly (fwi.co.uk)

Measuring your carbon impact - which is the right tool? - Kite Consulting

Farm-based carbon audits - FINAL (climatexchange.org.uk)

You can also find historic AHDB advice for cereals and oilseeds here:

Carbon footprinting for cereals and oilseeds | AHDB