Carbon Footprint Calculator

How it works

1. 1Enter your annual electricity use (kWh) and your grid’s emission factor (kg CO₂ per kWh) to calculate electricity emissions.
2. 2Add your yearly car distance (km) and vehicle emission factor (kg CO₂ per km), then your flight hours and a per-hour emission factor.
3. 3The calculator sums all three sources (amount × factor each) and divides the total by 21 kg per tree per year to show trees needed to offset your footprint.

Use cases

• Households wanting to understand which activity — electricity, driving, or flying — contributes most to their annual CO₂ output.
• Individuals planning to purchase carbon offsets and needing a tree-equivalent estimate for their yearly footprint.
• Students and educators demonstrating how emission factors and activity levels combine to produce a personal carbon footprint.

Frequently asked questions

How is my carbon footprint calculated?

Each source uses the formula CO₂ = activity amount × emission factor. For example, 3 500 kWh × 0.4 kg CO₂/kWh = 1 400 kg from electricity. The three results are summed to give your annual total.

Why does the grid emission factor matter so much?

Grid factors range from roughly 0.02 kg CO₂/kWh (hydro-heavy grids like Norway) to over 0.9 kg CO₂/kWh (coal-heavy grids). Using the right factor for your country or region makes your electricity estimate far more accurate.

How many trees does it actually take to offset one tonne of CO₂?

A mature tree absorbs roughly 21 kg of CO₂ per year, so offsetting 1 tonne (1 000 kg) requires about 48 trees growing for a full year. The calculator uses this 21 kg figure; actual sequestration varies with tree species, age, and climate.