How our calculations work
Karbonet is aligned with the GHG Protocol Corporate Standard and uses recognised, publicly published emission factors. Every number is traceable to a published source and a dated factor version.
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). Retired carbon credits are recorded as negative CO₂e and always reported separately from gross emissions.
2. Emission factors
Factors are classified by GHG Protocol scope. The source is cited on every row; the table shows the current vintage.
Current factor vintage: 2024. Grid electricity is shown once (global average); 55 country-specific grid factors are applied automatically by the company’s country.
Scope 1 — Direct
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| CNG | kg | 2.54 | DEFRA 2024 (approx.) |
| Coal (industrial) | kg | 2.4 | 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.) |
| Natural gas | m3 | 2.02 | DEFRA 2024 (approx.) |
| Petrol | liter | 2.31 | DEFRA 2024 (approx.) |
| Wood pellets (non-CO2 component) | kg | 0.052 | DEFRA 2024 (approx.) — biogenic CO2 outside scopes |
| Manufacturing process | kg | 1 | process estimate |
| Refrigerant R-134a | kg | 1300 | IPCC AR5 GWP |
| Refrigerant R-22 (HCFC) | kg | 1760 | IPCC AR5 GWP |
| Refrigerant R-32 | kg | 677 | IPCC AR5 GWP |
| Refrigerant R-404A | kg | 3943 | IPCC AR5 GWP |
| Refrigerant R-407C | kg | 1624 | IPCC AR5 GWP |
| Refrigerant R-410A | kg | 1924 | IPCC AR5 GWP |
| Refrigerant R-507A | kg | 3985 | IPCC AR5 GWP |
| SF₆ (switchgear) | kg | 23500 | IPCC AR5 GWP |
| Company HGV | km | 0.86 | DEFRA 2024 (approx.) |
| Company van | km | 0.24 | DEFRA 2024 (approx.) |
| Company car (avg) | km | 0.17 | DEFRA 2024 (approx.) |
| Motorbike | km | 0.113 | DEFRA 2024 (approx.) |
Scope 2 — Purchased energy
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| District heat | kWh | 0.171 | DEFRA 2024 (approx.) |
| Grid electricity | kWh | 0.45 | IEA grid avg |
Scope 3 — Value chain
| Activity | Unit | kg CO₂e | Source |
|---|---|---|---|
| Air freight (long-haul, incl. RF) | tkm | 1.13 | DEFRA 2024 (approx.) |
| Rail freight | tkm | 0.027 | DEFRA 2024 (approx.) |
| Sea freight (container) | tkm | 0.016 | DEFRA 2024 (approx.) |
| Road freight (HGV avg) | tkm | 0.107 | GLEC freight |
| Aluminium | kg | 6.7 | DEFRA 2024 (approx.) |
| Cement | kg | 0.9 | DEFRA 2024 (approx.) |
| Glass | kg | 0.85 | DEFRA 2024 (approx.) |
| Paper & board | kg | 0.919 | DEFRA 2024 (approx.) |
| Plastic (avg) | kg | 3.1 | DEFRA 2024 (approx.) |
| Steel | kg | 1.9 | DEFRA 2024 (approx.) |
| Timber | kg | 0.32 | DEFRA 2024 (approx.) |
| Capital goods | kg | 2.5 | DEFRA capital |
| Purchased goods (avg) | kg | 1.2 | DEFRA spend-based |
| Business travel (avg mode) | km | 0.222 | DEFRA 2024 (approx.) |
| Coach travel | pkm | 0.027 | DEFRA 2024 (approx.) |
| Employee commuting (avg) | km | 0.16 | DEFRA 2024 (approx.) |
| Flight — domestic (incl. RF) | pkm | 0.246 | DEFRA 2024 (approx.) |
| Flight — long-haul economy (incl. RF) | pkm | 0.148 | DEFRA 2024 (approx.) |
| Flight — short-haul (incl. RF) | pkm | 0.151 | DEFRA 2024 (approx.) |
| Hotel night (world avg) | night | 25 | DEFRA 2024 (approx.) |
| Rail travel | pkm | 0.035 | DEFRA 2024 (approx.) |
| Taxi | km | 0.148 | DEFRA 2024 (approx.) |
| Waste — landfill (mixed) | kg | 0.458 | DEFRA landfill |
| Waste — composting (organic) | kg | 0.01 | DEFRA 2024 (approx.) |
| Waste — incineration (energy recovery) | kg | 0.021 | DEFRA 2024 (approx.) |
| Waste — recycling (mixed) | kg | 0.021 | DEFRA 2024 (approx.) |
| Wastewater treatment | m3 | 0.272 | DEFRA 2024 (approx.) |
| Water supply | m3 | 0.344 | DEFRA water |
Factors are versioned by publication year. Each record keeps the factor that was valid on its activity date, so past reports never change when a new vintage is loaded. Grid factors come from IEA/Ember electricity data; freight from the GLEC Framework; fuels, travel, waste and materials from the UK DEFRA/DESNZ conversion factors. For CBAM reporting, installation-specific actual data is used wherever it is available and EU default values are flagged where they are applied.
Factor = fuel carbon content × oxidation rate × 44/12 (C→CO₂ molecular weight). DEFRA publishes this per litre/m³. Complete combustion is assumed.
Factor = generation-mix weighted average emissions of the country grid (IEA/Ember). Selected by the company’s country; the global average is used where no country factor is published.
GLEC Framework: kg CO₂e per tonne-kilometre (tkm). 1 tkm = moving 1 tonne of goods 1 km.
Mass-based average: DEFRA material-use factors in kg CO₂e per kg of product. Supplier actual data is preferred whenever it is available.
Scope 2: location-based and market-based
We report both figures required by the GHG Protocol Scope 2 Guidance. Location-based uses your country’s average grid factor. Market-based applies your contractual instruments (guarantees of origin, I-RECs, PPAs, green tariffs); consumption not covered by a contract uses the AIB residual mix where one is published, otherwise the grid factor.
CBAM embedded emissions
For CBAM goods we calculate specific embedded emissions per tonne at installation level: direct emissions of the production process, indirect emissions from the electricity consumed, and the embedded emissions of precursor materials — per CN code and reporting period, following Regulation (EU) 2023/956. Direct and indirect emissions are reported separately. Actual installation data is used; EU default values are flagged where they are applied. The declaration to the EU is filed by the importer; Karbonet produces the data pack it needs.
Factor versions & GWP
Factors are versioned by publication year. Every record stores the factor value, its source and the GWP basis (IPCC AR5, 100-year) that applied on its activity date.
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 3 | 2,400 km travelled (average mode) | 2,400 × 0.222 kg/km | 533 kg CO₂e |
| Road freight Scope 3 | 5 t × 300 km = 1,500 tkm | 1,500 × 0.107 kg/tkm | 160 kg CO₂e |
Retired carbon credits (negative records)
| Activity | Input | Calculation | Result |
|---|---|---|---|
| Retired carbon credit | 5 t CO₂e · registry credit · serial number · retirement certificate attached | 5,000 × -1.0 | −5,000 kg CO₂e |
Only third-party credits that are retired in a recognised registry (for example Gold Standard or Verra) are recorded, with the registry serial number and the retirement certificate. They are stored as negative CO₂e and always reported separately from your gross emissions. Tree planting and renewable generation are not offsets: renewable electricity is reported under market-based Scope 2 (see above) and plantings are shown for information only.
4. Net-zero status
Offset coverage = offsets ÷ gross × 100. It is shown next to the reduction plan and the declared target year; buying credits alone does not move the reduction trajectory.
Recognised standards (SBTi Corporate 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. Karbonet always ranks reduction tips ahead of offsetting, and keeps a proof document and an on-chain anchor for every offset record.
The status shown in Karbonet is an internal progress indicator. It is not a certification of carbon neutrality or net zero under any standard and must not be used as a public environmental claim; Karbonet is not an accredited verification body.
5. Real-world equivalences
To make abstract kilograms tangible, the net footprint is also expressed with reference values:
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 anchoring
For each record and report, a SHA-256 content hash (record hash) is computed and written to a low-energy EVM blockchain (SciMatic). This creates a timestamped, tamper-evident anchor: anyone can confirm on the public explorer that this exact hash existed at that time, and any later change to the record would produce a different hash. Only the hash goes on-chain — your data stays in your account.
What your auditor receives
A read-only, time-boxed auditor portal with the full ledger, the factor applied to every record, generated reports and their on-chain proofs, plus a verifier export (CSV) that reconciles to the report totals.
Sources
- GHG Protocol Corporate Standard
- GHG Protocol Scope 2 Guidance
- UK DEFRA / DESNZ — GHG Conversion Factors
- IEA — Emissions Factors
- Ember — Yearly Electricity Data
- AIB — European Residual Mixes
- IPCC AR5 WG1 — GWP values (Chapter 8)
- US EPA — GHG Equivalencies Calculator
- GLEC Framework (Smart Freight Centre)
- ISO 14064-1:2018
- ISO 14068-1:2023
- SBTi — Corporate Net-Zero Standard
- EU CBAM — Regulation (EU) 2023/956