Carbon Footprint Calculator
Enter an activity amount (e.g. electricity kWh) and the corresponding emission factor to compute the carbon footprint CF = activity × emission factor (kg CO₂e), quantifying greenhouse-gas emissions of that activity.
Input Data
Results
At a glance:Enter an activity amount (e.g. electricity kWh) and the corresponding emission factor to compute the carbon footprint CF = activity × emission factor (kg CO₂e), quantifying greenhouse-gas emissions of that activity.
Formula
CF = activity × emission factor (kg CO₂e).
How to Use
- Enter the activity amount and its emission factor.
- The calculator returns the carbon footprint in kg CO₂e.
Emission factors for common activities (illustrative)
| Activity | Emission factor | Unit |
|---|---|---|
| Hong Kong electricity | ≈ 0.66 | kg CO₂e / kWh |
| Gasoline | ≈ 2.3 | kg CO₂e / L |
| Diesel | ≈ 2.7 | kg CO₂e / L |
| Piped natural gas | ≈ 2.0 | kg CO₂e / m³ |
| Example: 300 kWh × 0.66 | = 198 | kg CO₂e |
Emission factors vary by region and year; use the latest official local value.
FAQ
What does the unit CO₂e mean?
CO₂e (carbon-dioxide equivalent) converts different greenhouse gases (e.g. methane, nitrous oxide) by their Global Warming Potential (GWP) into a unified 'equivalent mass of CO₂', making multiple gases summable and comparable. Carbon footprint is usually expressed in kg or tonnes CO₂e.
What is Hong Kong's electricity emission factor?
Hong Kong's grid emits about 0.66 kg CO₂e per kWh; the actual figure is published yearly by the two power companies from their fuel mix and trends down as gas and renewables rise. For precise accounting, use the official current-year value for your supply zone.
How do I compute a whole household's total carbon footprint?
Convert each activity by its own factor and add them: total CF = Σ(activity × factor), covering electricity, gas, transport fuel, water, and waste. This tool does one item at a time; compute each then sum for the complete footprint.
How to effectively reduce the carbon footprint?
Two directions: reduce activity (save electricity, drive less, cut waste) and lower the factor (energy-efficient appliances, clean energy). Start with the largest share (usually electricity and transport) for the clearest benefit.
Why do different tools give different footprints?
Mainly because emission-factor sources, regions, years, and scopes differ. Some factors count only combustion (scope 1/2), others include upstream extraction and transport life-cycle emissions (scope 3); grid structure varies by region. Always compare with consistent factor scope and the applicable local current value.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.