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How is my estimated carbon footprint calculated? 

Your estimated carbon footprint is based on the total transaction amount, and not the individual items making up that purchase.

The Westpac App uses two pieces of data to calculate your estimated monthly carbon footprint: the transaction amount, and the transaction’s industry category which has an associated emissions factor calculated based on Australian industry average data. Each eligible transaction is multiplied by an 'emissions factor' (how much greenhouse gas that type of activity emits per dollar spent) to work out the estimated carbon footprint for that transaction.

Our partner, Cogo, has provided these emission factors, mapped to their comprehensive database of industry categories (e.g., home energy, petrol, groceries, fashion, etc) for Australia. For example, $50 spent at an Australian grocery retailer creates, on average, 17.8kg CO2e, the equivalent of driving an average car for 100km. 

When calculating averages, the national average is an estimate of the per capita Australian carbon footprint and is based off average Australian consumption data provided by the Australian Department of Climate Change, Energy, the Environment and Water. The household average is calculated by multiplying this figure by 2.6, the number of people in an average Australian household.

These figures are shown to give you an idea of Australian averages and shouldn’t be considered a benchmark, or specific to your individual or household consumption. 


To help you understand how the Carbon Footprint Tracker feature works, our partner Cogo has provided answers to your most frequently asked questions.