New emissions calculator gives farmers a clearer picture of on-farm greenhouse gases

A new online tool is now available to help farmers estimate and understand their on-farm greenhouse gas emissions, using a consistent, science-backed method tailored to New Zealand’s agricultural systems. 

Developed by the Ministry for Primary Industries (MPI) in collaboration with the Bioeconomy Science Institute (BSI) and the Ag Emissions Centre, the On-Farm Emissions Calculator is live at calculator.agmatters.nz(external link).

While more than 10 emissions calculators already exist across the agriculture and horticulture sectors, the Calculator is the first to apply the government-mandated standard released in December 2024. This ensures farmers can estimate their emissions using the same nationally recognised methodology, anchored in New Zealand’s official greenhouse gas inventory. 

Designed to be simple, reliable, and accessible, the Calculator supports farmers who do not receive emissions estimates from processors or life cycle assessments. It provides a consistent way to calculate emissions from livestock and fertiliser inputs, presenting results as methane and nitrous oxide, New Zealand’s two key agricultural greenhouse gases. 

Bioeconomy Science Institute - AgResearch Group Chief Scientist Axel Heiser said,  “The On-Farm Emissions Calculator puts decades of scientific research directly into the hands of farmers. It combines robust emissions inventory data with key farm metrics to deliver the most accurate picture yet of where farmers stand.” 

Farmers input basic farm data, such as livestock numbers and fertiliser use, and receive an emissions estimate in line with the national inventory. The Calculator was tested by farmers at the 2025 National Fieldays to ensure it reflects real-world farm practices and is easy to use. Feedback was overwhelmingly positive. 

With around 80 percent of New Zealand’s export markets introducing mandatory greenhouse gas reporting requirements, it is increasingly important for farmers to understand and manage their emissions. The Calculator provides a practical and transparent way to do just that, supporting market claims, reducing risk for exporters, and helping farmer-owned co-operatives and marketers meet international expectations. 

The Calculator can be used anonymously or via a registered account. A clear data privacy policy ensures farmers retain full control of their information. It will be updated annually to reflect changes to New Zealand’s national greenhouse gas inventory, maintaining consistency between farm-level and national-level reporting.