How our calculations work
GreenLedger follows the GHG Protocol methodology and uses recognized, publicly published emission factors. Every number is auditable and cited.
1. The core formula
Every emission record is computed by multiplying activity data by an emission factor:
This is the foundational approach of the GHG Protocol Corporate Standard. Emissions are classified into three scopes (below). Carbon offsets are recorded as negative CO₂e.
2. Emission factors
Factors are classified by GHG Protocol scope definitions. Sources are cited per row.
Scope 1 — Direct
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| Cng | kg | 2.54 | DEFRA 2024 (approx.) |
| Coal industrial | kg | 2.4 | DEFRA 2024 (approx.) |
| Company hgv | km | 0.86 | DEFRA 2024 (approx.) |
| Company van | km | 0.24 | DEFRA 2024 (approx.) |
| Company vehicle | km | 0.17 | DEFRA 2024 (approx.) |
| Diesel | liter | 2.68 | DEFRA 2024 (approx.) |
| Fuel oil | liter | 3.18 | DEFRA 2024 (approx.) |
| Kerosene | liter | 2.54 | DEFRA 2024 (approx.) |
| Lpg | liter | 1.56 | DEFRA 2024 (approx.) |
| Manufacturing | kg | 1 | process estimate |
| Motorbike | km | 0.113 | DEFRA 2024 (approx.) |
| Natural gas | m3 | 2.02 | DEFRA 2024 (approx.) |
| Petrol | liter | 2.31 | DEFRA 2024 (approx.) |
| Refrigerant r134a | kg | 1,300 | IPCC AR5 GWP |
| Refrigerant r22 | kg | 1,760 | IPCC AR5 GWP |
| Refrigerant r32 | kg | 677 | IPCC AR5 GWP |
| Refrigerant r404a | kg | 3,943 | IPCC AR5 GWP |
| Refrigerant r407c | kg | 1,624 | IPCC AR5 GWP |
| Refrigerant r410a | kg | 1,924 | IPCC AR5 GWP |
| Refrigerant r507a | kg | 3,985 | IPCC AR5 GWP |
| Sf6 | kg | 23,500 | IPCC AR5 GWP |
| Wood pellets | kg | 0.052 | DEFRA 2024 (approx.) — biogenic CO2 outside scopes |
Scope 2 — Purchased Energy
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| District heat | kWh | 0.171 | DEFRA 2024 (approx.) |
| Electricity | kWh | 0.45 | IEA grid avg |
| Electricity | kWh | 0.4 | Ember/IEA 2023–24 grid (TR) |
| Electricity | kWh | 0.38 | Ember/IEA 2023–24 grid (DE) |
| Electricity | kWh | 0.056 | Ember/IEA 2023–24 grid (FR) |
| Electricity | kWh | 0.207 | Ember/IEA 2023–24 grid (GB) |
| Electricity | kWh | 0.17 | Ember/IEA 2023–24 grid (ES) |
| Electricity | kWh | 0.33 | Ember/IEA 2023–24 grid (IT) |
| Electricity | kWh | 0.33 | Ember/IEA 2023–24 grid (NL) |
| Electricity | kWh | 0.12 | Ember/IEA 2023–24 grid (BE) |
| Electricity | kWh | 0.66 | Ember/IEA 2023–24 grid (PL) |
| Electricity | kWh | 0.025 | Ember/IEA 2023–24 grid (SE) |
| Electricity | kWh | 0.028 | Ember/IEA 2023–24 grid (NO) |
| Electricity | kWh | 0.15 | Ember/IEA 2023–24 grid (DK) |
| Electricity | kWh | 0.08 | Ember/IEA 2023–24 grid (FI) |
| Electricity | kWh | 0.1 | Ember/IEA 2023–24 grid (AT) |
| Electricity | kWh | 0.035 | Ember/IEA 2023–24 grid (CH) |
| Electricity | kWh | 0.15 | Ember/IEA 2023–24 grid (PT) |
| Electricity | kWh | 0.34 | Ember/IEA 2023–24 grid (GR) |
| Electricity | kWh | 0.41 | Ember/IEA 2023–24 grid (CZ) |
| Electricity | kWh | 0.26 | Ember/IEA 2023–24 grid (RO) |
| Electricity | kWh | 0.37 | Ember/IEA 2023–24 grid (BG) |
| Electricity | kWh | 0.2 | Ember/IEA 2023–24 grid (HU) |
| Electricity | kWh | 0.28 | Ember/IEA 2023–24 grid (IE) |
| Electricity | kWh | 0.24 | Ember/IEA 2023–24 grid (UA) |
| Electricity | kWh | 0.38 | Ember/IEA 2023–24 grid (US) |
| Electricity | kWh | 0.13 | Ember/IEA 2023–24 grid (CA) |
| Electricity | kWh | 0.44 | Ember/IEA 2023–24 grid (MX) |
| Electricity | kWh | 0.096 | Ember/IEA 2023–24 grid (BR) |
| Electricity | kWh | 0.3 | Ember/IEA 2023–24 grid (AR) |
| Electricity | kWh | 0.29 | Ember/IEA 2023–24 grid (CL) |
| Electricity | kWh | 0.16 | Ember/IEA 2023–24 grid (CO) |
| Electricity | kWh | 0.58 | Ember/IEA 2023–24 grid (CN) |
| Electricity | kWh | 0.71 | Ember/IEA 2023–24 grid (IN) |
| Electricity | kWh | 0.46 | Ember/IEA 2023–24 grid (JP) |
| Electricity | kWh | 0.43 | Ember/IEA 2023–24 grid (KR) |
| Electricity | kWh | 0.68 | Ember/IEA 2023–24 grid (ID) |
| Electricity | kWh | 0.62 | Ember/IEA 2023–24 grid (VN) |
| Electricity | kWh | 0.45 | Ember/IEA 2023–24 grid (TH) |
| Electricity | kWh | 0.59 | Ember/IEA 2023–24 grid (MY) |
| Electricity | kWh | 0.61 | Ember/IEA 2023–24 grid (PH) |
| Electricity | kWh | 0.42 | Ember/IEA 2023–24 grid (PK) |
| Electricity | kWh | 0.57 | Ember/IEA 2023–24 grid (BD) |
| Electricity | kWh | 0.55 | Ember/IEA 2023–24 grid (AU) |
| Electricity | kWh | 0.11 | Ember/IEA 2023–24 grid (NZ) |
| Electricity | kWh | 0.39 | Ember/IEA 2023–24 grid (SG) |
| Electricity | kWh | 0.66 | Ember/IEA 2023–24 grid (KZ) |
| Electricity | kWh | 0.47 | Ember/IEA 2023–24 grid (AZ) |
| Electricity | kWh | 0.43 | Ember/IEA 2023–24 grid (AE) |
| Electricity | kWh | 0.6 | Ember/IEA 2023–24 grid (SA) |
| Electricity | kWh | 0.49 | Ember/IEA 2023–24 grid (QA) |
| Electricity | kWh | 0.53 | Ember/IEA 2023–24 grid (IL) |
| Electricity | kWh | 0.47 | Ember/IEA 2023–24 grid (EG) |
| Electricity | kWh | 0.71 | Ember/IEA 2023–24 grid (ZA) |
| Electricity | kWh | 0.36 | Ember/IEA 2023–24 grid (NG) |
| Electricity | kWh | 0.09 | Ember/IEA 2023–24 grid (KE) |
| Electricity | kWh | 0.62 | Ember/IEA 2023–24 grid (MA) |
| Electricity residual | kWh | 0.21 | AIB residual mix 2023 (AT, approx.) |
| Electricity residual | kWh | 0.25 | AIB residual mix 2023 (BE, approx.) |
| Electricity residual | kWh | 0.03 | AIB residual mix 2023 (CH, approx.) |
| Electricity residual | kWh | 0.65 | AIB residual mix 2023 (DE, approx.) |
| Electricity residual | kWh | 0.47 | AIB residual mix 2023 (DK, approx.) |
| Electricity residual | kWh | 0.41 | AIB residual mix 2023 (ES, approx.) |
| Electricity residual | kWh | 0.33 | AIB residual mix 2023 (FI, approx.) |
| Electricity residual | kWh | 0.06 | AIB residual mix 2023 (FR, approx.) |
| Electricity residual | kWh | 0.35 | AIB residual mix 2023 (GB, approx.) |
| Electricity residual | kWh | 0.55 | AIB residual mix 2023 (GR, approx.) |
| Electricity residual | kWh | 0.46 | AIB residual mix 2023 (IE, approx.) |
| Electricity residual | kWh | 0.46 | AIB residual mix 2023 (IT, approx.) |
| Electricity residual | kWh | 0.51 | AIB residual mix 2023 (NL, approx.) |
| Electricity residual | kWh | 0.4 | AIB residual mix 2023 (NO, approx.) |
| Electricity residual | kWh | 0.79 | AIB residual mix 2023 (PL, approx.) |
| Electricity residual | kWh | 0.3 | AIB residual mix 2023 (PT, approx.) |
| Electricity residual | kWh | 0.04 | AIB residual mix 2023 (SE, approx.) |
| Electricity residual | kWh | 0.45 | AIB residual mix 2023 (TR, approx.) |
Scope 3 — Value Chain
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| Air freight | tkm | 1.13 | DEFRA 2024 (approx.) |
| Business travel | km | 0.222 | DEFRA 2024 (approx.) |
| Capital goods | kg | 2.5 | DEFRA capital |
| Coach travel | pkm | 0.027 | DEFRA 2024 (approx.) |
| Employee commute | km | 0.16 | DEFRA 2024 (approx.) |
| Flight domestic | pkm | 0.246 | DEFRA 2024 (approx.) |
| Flight long haul | pkm | 0.148 | DEFRA 2024 (approx.) |
| Flight short haul | pkm | 0.151 | DEFRA 2024 (approx.) |
| Hotel night | night | 25 | DEFRA 2024 (approx.) |
| Material aluminium | kg | 6.7 | DEFRA 2024 (approx.) |
| Material cement | kg | 0.9 | DEFRA 2024 (approx.) |
| Material glass | kg | 0.85 | DEFRA 2024 (approx.) |
| Material paper | kg | 0.919 | DEFRA 2024 (approx.) |
| Material plastic | kg | 3.1 | DEFRA 2024 (approx.) |
| Material steel | kg | 1.9 | DEFRA 2024 (approx.) |
| Material timber | kg | 0.32 | DEFRA 2024 (approx.) |
| Purchased goods | kg | 1.2 | DEFRA spend-based |
| Rail freight | tkm | 0.027 | DEFRA 2024 (approx.) |
| Rail travel | pkm | 0.035 | DEFRA 2024 (approx.) |
| Sea freight | tkm | 0.016 | DEFRA 2024 (approx.) |
| Taxi | km | 0.148 | DEFRA 2024 (approx.) |
| Upstream transport | tkm | 0.107 | GLEC freight |
| Waste | kg | 0.458 | DEFRA landfill |
| Waste composting | kg | 0.01 | DEFRA 2024 (approx.) |
| Waste incineration | kg | 0.021 | DEFRA 2024 (approx.) |
| Waste recycling | kg | 0.021 | DEFRA 2024 (approx.) |
| Wastewater | m3 | 0.272 | DEFRA 2024 (approx.) |
| Water supply | m3 | 0.344 | DEFRA water |
Factors are reviewed against the latest published values (UK DEFRA/DESNZ annual conversion factors, IEA grid averages, GLEC freight). For CBAM reporting, installation-specific actual data is preferred over defaults where available.
Factor = fuel carbon content × oxidation rate × 44/12 (C→CO₂ molecular weight). DEFRA publishes this per litre/m³. Complete combustion assumed.
Factor = generation-mix weighted average emissions of the country grid (IEA/Ember). Türkiye ≈ 0.40 kg/kWh; global average 0.45. Selected by the company’s country.
GLEC framework: kg CO₂e per tonne-kilometre (tkm). 1 tkm = moving 1 tonne of goods 1 km.
Spend/mass-based: DEFRA sector-average kg CO₂e per kg of product. Supplier actual data is preferred when available.
3. Worked examples
Every number you see in the app is computed with the explicit arithmetic below. These examples are generated live from the actual factor values.
| Activity | Input | Calculation | Result |
|---|---|---|---|
| ⛽ Burning diesel Scope 1 | 850 litres of diesel burned | 850 × 2.68 kg/L | 2,278 kg CO₂e |
| ⛽ Burning petrol Scope 1 | 400 litres of petrol | 400 × 2.31 kg/L | 924 kg CO₂e |
| 🔥 Natural gas Scope 1 | 3,200 m³ of natural gas | 3,200 × 2.02 kg/m³ | 6,464 kg CO₂e |
| ⚡ Electricity (Türkiye) Scope 2 | 12,500 kWh · TR grid | 12,500 × 0.40 kg/kWh | 5,000 kg CO₂e |
| ✈️ Business travel Scope 1 | 2,400 km flown | 2,400 × 0.222 kg/km | 533 kg CO₂e |
| 🚚 Freight Scope 3 | 5 t × 300 km = 1,500 tkm | 1,500 × 0.107 kg/tkm | 161 kg CO₂e |
Carbon offsets (negative records)
| 🌳 Planting trees | 100 mature trees · annual | 100 × 21 kg/tree·yr | −2,100 kg CO₂e |
| ⚡ Renewable energy | 10 MWh clean generation | 10 × 450 kg/MWh | −4,500 kg CO₂e |
Offset records are stored as negative (−) CO₂e to reduce the net footprint. Tree sequestration uses ≈ 21 kg per mature tree per year; renewable generation uses grid displacement ≈ 450 kg/MWh.
4. Net-zero status
Progress to net zero = offsets ÷ gross × 100.
Recognized standards (SBTi Net-Zero Standard, ISO 14068-1:2023) require emission reductions first; offsetting is only for residual, unavoidable emissions. Credits must be additional, permanent, non-double-counted and retired. GreenLedger always ranks reduction tips ahead of offsetting, and supports a proof document + on-chain record for every offset.
5. Real-world equivalences
To make abstract kilograms tangible, the net footprint is converted using reference values from the US EPA Greenhouse Gas Equivalencies Calculator:
Equivalences are illustrative only; official reporting uses absolute kg CO₂e values.
6. Net-zero projection
The projection assumes the current offset run-rate continues linearly and compares it to the company’s declared target year (on track / ahead / behind). It is a simplified estimate — it does not model reduction measures and is not a guarantee.
7. Blockchain verification
For each record, a SHA-256 content hash (record hash) is computed and written to a low-energy EVM blockchain (Scimatic). This creates a timestamped, immutable proof of the record — auditors can verify it independently.