Help, Methodologies & FAQs
Transparent carbon calculations powered by 20 years of expertise and our proprietary CaDI™ (Carbon Data Intelligence) platform.
For Individuals
Looking to understand your personal impact? Our free online calculator provides a robust snapshot of your lifestyle emissions, from flights to home energy.
Start Free CalculationFor Business & Net Zero
Need auditable data for ISO reporting, SECR, or Supply Chain auditing? Move beyond basic calculators to Sustrax, our professional carbon management operating system.
Explore Sustrax PlatformOur Methodology & Data Integrity
At Carbon Footprint Ltd, we believe in Radical Transparency. Our calculations are not estimates; they are based on official country-specific factors (e.g., UK Government GHG Conversion Factors) and scientific data.
- Country Specific: We apply grid electricity factors relevant to the country where you live/operate.
- Official Standards: All factors are derived from reputable sources like DEFRA/BEIS and international energy agencies.
- Proprietary Data: Our tools also use data from CaDI, our carbon database of 50,000+ emission factors.
Calculation Details by Category
🏠 House & Buildings
How do you calculate household emissions?
We use the energy consumption data you provide (kWh of electricity, gas, coal, etc.) and multiply it by the specific carbon ratio for your country's energy grid.
What does the "Number of People" affect?
This splits the total household footprint by the number of residents, giving you a "per person" result to compare against national averages.
✈️ Flights
How are flight emissions calculated?
We calculate the "Great Circle" distance between airports. We then apply an emissions factor based on the flight length (Short, Medium, Long Haul) and class of travel.
🚗 Car & Motorbike
Which method is most accurate?
We offer three levels of accuracy based on the data you have:
- Year/Make/Model (Most Accurate): Uses official manufacturer efficiency data.
- Mileage & MPG: Calculates based on your specific fuel efficiency.
- Distance Only: Uses a national average for your vehicle type.
🚆 Bus & Rail
Where does the data come from?
Calculations are based on national average factors for public transport per passenger-kilometer. This accounts for the average occupancy of trains and buses in your region.
🛍️ Secondary Footprint
What is this?
This measures the carbon embedded in the things you buy (clothes, food, insurance, IT equipment). It is often a significant part of your footprint.
How is it calculated?
We use "Spend-Based Analysis" utilizing standard industrial input-output tables to estimate emissions per £/$ spent in various categories.
📊 Interpreting Results
What does the total show?
Your result represents your total CO2 equivalent (CO2e) emissions in metric tonnes. We compare this against the national average and a global "World Target" to give you context.
Why is the target so low?
To combat climate change, the global average per person needs to drop significantly. Our Net Zero Standard helps plot a course to this target.