A carbon footprint is the total amount of greenhouse gases, primarily carbon dioxide, that are emitted directly or indirectly by human activities. It is usually measured in equivalent tons of CO₂. Here’s a breakdown:
Direct Emissions: These come from activities like driving a car, using electricity and gas in our homes, and any other direct consumption of fossil fuels.
Indirect Emissions: These are associated with the entire lifecycle of products we use, from production to disposal. For instance, the carbon footprint of a smartphone includes emissions from mining the raw materials, manufacturing, shipping, and eventual disposal.
The goal is to reduce our carbon footprint to mitigate the impact of climate change. Some common strategies include using renewable energy sources, improving energy efficiency, and supporting sustainable practices.
Use our carbon footprint calculator to calculate the direct emissions of your household.
How is your carbon footprint calculated?
To calculate the direct emissions of a household, the following formulas were used:
Electricity usage
User Input: kWh per year
Formula: Total kWh/year×0.7÷1000\Total kWh/year \times 0.7 \div 1000Total kWh/year×0.7÷1000
(0.7 kg CO₂e per kWh, converted to tonnes)
Gas usage
User Input: MJ per year
Formula: Total MJ/year×51.53÷1000000\Total MJ/year \times 51.53 \div 1000000Total MJ/year×51.53÷1000000
(51.53 kg CO₂e per GJ, where 1 GJ = 1000 MJ, converted to tonnes)
Water usage
User Input: Litres per year
Formula: Total Litres/year×0.0003÷1000\Total Litres/year \times 0.0003 \div 1000Total Litres/year×0.0003÷1000
(0.0003 kg CO₂e per litre, converted to tonnes)
Solar panel offset
User Input: System Size (kW)
Formula: System Size×1500×−0.7÷1000\System Size \times 1500 \times -0.7 \div 1000System Size×1500×−0.7÷1000
(Each kW produces 1500 kWh per year, offsetting 0.7 kg CO₂e per kWh, converted to tonnes, negative value for offset)
Battery storage offset
User Input: Battery Capacity (kWh)
Formula: Battery Capacity×200×−0.5÷1000\Battery Capacity}\times 200 \times -0.5 \div 1000Battery Capacity×200×−0.5÷1000
(Each kWh of battery offsets 200 kWh of grid electricity per year, at 0.5 kg CO₂e per kWh, negative value for offset)
Public transport (Trips per Week, converted to yearly)
User Input: Trips per week
Formula: Total Trips/week×52×0.1\Total Trips/week \times 52 \times 0.1Total Trips/week×52×0.1
(Each trip emits 0.1 tonnes CO₂e per year, weekly input converted to yearly)
Flights (Short-haul & Long-haul, per year)
User Input: Flights per year
Formula: (Short-haul Flights×0.3)+(Long-haul Flights×1.5)(\{Short-haul Flights \times 0.3) + (\Long-haul Flights \times 1.5)(Short-haul Flights×0.3)+(Long-haul Flights×1.5)
(Short-haul = 0.3 tonnes CO₂e per flight, Long-haul = 1.5 tonnes CO₂e per flight)
Waste management (Landfill bins per week, converted to yearly)
User Input: Bins per week
Formula: Total Bins/week×52×0.2\Total Bins/week \times 52 \times 0.2Total Bins/week×52×0.2
(Each full landfill bin produces 0.2 tonnes CO₂e, weekly input converted to yearly)
Diet type (fixed emissions per year)
User Input: Dropdown (Meat-heavy, Mixed, Vegetarian, Vegan)
Values: Meat-heavy: 3.3 tonnes CO₂e, Mixed: 2.5 tonnes CO₂e, Vegetarian: 1.7 tonnes CO₂e, Vegan: 1.5 tonnes CO₂e
Car ownership & type
User Input: Number of Cars + Type (ICE, Hybrid, BEV)
Formula: (ICE Cars×2.4)+(Hybrid Cars×1.2)+(BEV Cars×0.5)(\ICE Cars \times 2.4) + (Hybrid Cars \times 1.2) + (BEV Cars \times 0.5)(ICE Cars×2.4)+(Hybrid Cars×1.2)+(BEV Cars×0.5)
(ICE = 2.4 tonnes CO₂e/year, Hybrid = 1.2 tonnes CO₂e/year, BEV = 0.5 tonnes CO₂e/year)
Is the calculation accurate?
All the formulas use emissions data based on averages across Australia. The calculation does not take into account:
- Brands/models of appliances or vehicles
- Vehicle types not listed
- Different usage habits of individuals within a household
- The type or volume of waste disposed of each week
- The aircraft utilised in short or long-haul flights, nor the exact distance or fuel usage
- The daily food consumption of each individual
- Any indirect emissions
The calculator is intended to be used as a guide only.
What is CO₂e?
CO₂e stands for “carbon dioxide equivalent.” It’s a standardised way of measuring greenhouse gases (GHGs) based on their global warming potential relative to CO₂ over a specific time period, usually 100 years. Essentially, CO₂e allows us to express the impact of different GHGs, like methane (CH₄) and nitrous oxide (N₂O), in terms of the amount of CO₂ that would have the same warming effect.
For example:
Methane (CH₄) is about 25 times more potent than CO₂ over a 100-year period, so 1 ton of CH₄ is equivalent to 25 tons of CO₂e.
Nitrous oxide (N₂O) is about 298 times more potent than CO₂, so 1 ton of N₂O is equivalent to 298 tons of CO₂e.
Importance of reducing CO₂e
Reducing CO₂e is critical for several reasons:
Climate change mitigation: High levels of CO₂e contribute to global warming and climate change, leading to more extreme weather events, rising sea levels, and disruptions to ecosystems.
Health benefits: Reducing emissions can improve air quality, leading to better respiratory and cardiovascular health for communities.
Economic savings: Energy efficiency and renewable energy often result in long-term cost savings. Additionally, reducing emissions can protect economies from the adverse impacts of climate change, such as damage to infrastructure and agriculture.
Sustainability: Lowering our CO₂e emissions supports sustainable development, ensuring that future generations have access to clean air, water, and other resources.
How can I reduce my household's emissions?
There’s many practical ways to reduce your household’s carbon footprint:
Install solar panels: Generate clean energy and reduce reliance on fossil fuels.
Upgrade to energy-efficient appliances: Look for devices with high energy ratings.
Improve home insulation: Reduce the need for heating and cooling by enhancing your home’s insulation.
Use public transport or electric vehicles: Reduce direct emissions from personal transportation.
Support sustainable practices: Choose products and services that have lower carbon footprints.
Upgrading your inefficient systems and appliances is usually your first step to reducing your carbon footprint. Replacing an inefficient electric hot water system with a heat pump can reduce your energy bills by an average of $400 – $800 per year, and reduce your hot water electricity usage by 60-75%.
Read more about energy efficiency upgrades.
Installing solar is one of the best ways to reduce your carbon footprint and save money on your electricity bills. Get FREE quotes for solar, batteries and more.
