Methodology
How CO2Calc calculates CO₂ emissions
CO2Calc uses a fuel-based method with emission factors taken directly from official EU documents. This page lists every factor, its source and the formulas behind each result.
Our team monitors EU-regulated sources (EUR-Lex, JRC publications) and updates the factors when official values change. Last review: September 2026.
The formula
Every calculation starts from the fuel used on the trip:
CO₂ (kg) = Fuel used × Emission factor (kg CO₂e per litre or kg)
Intensity (g/km) = CO₂ ÷ Distance × 1000
Diesel and HVO are measured in litres; LNG and Bio-LNG in kilograms, the unit they are dispensed and reported in. When telematics reports LNG in litres, it is converted with a density of 0.45 kg/L.
Well-to-Wheel (WTW) and Tank-to-Wheel (TTW)
TTW covers what the engine emits while driving — the direct, tailpipe emissions. WTT (Well-to-Tank) covers producing, refining and transporting the fuel. WTW = WTT + TTW is the full fuel life cycle.
For fossil fuels WTW is higher than TTW. For renewable fuels it can be lower: the CO₂ released when burning HVO was absorbed by the plants it was made from, so its WTW is far below fossil diesel.
Emission factors
Diesel
kg CO₂e per litre- WTW
- 3.41
- WTT
- 0.78
- TTW
- 2.63
Source: WTW: Commission Implementing Regulation (EU) 2022/996 · TTW: JRC JEC Well-to-Wheels v5
LNG
kg CO₂e per kg- WTW
- 3.2472
- WTT
- 0.4772
- TTW
- 2.77
Source: WTW: Commission Implementing Regulation (EU) 2022/996 · TTW: JRC JEC Well-to-Wheels v5
Bio-LNG
kg CO₂e per kg- WTW
- -5.595
- WTT
- -5.595
- TTW
- 0
Source: Directive (EU) 2018/2001 (RED II/III) — bio-LNG from manure; TTW counted as 0 (biogenic CO₂)
HVO (Rapeseed)
kg CO₂e per litre- WTW
- 1.5572
- WTT
- 1.5164
- TTW
- 0.0408
Source: Directive (EU) 2018/2001 (RED II/III) — HVO from rapeseed oil
HVO (Waste)
kg CO₂e per litre- WTW
- 0.4046
- WTT
- 0.3638
- TTW
- 0.0408
Source: Directive (EU) 2018/2001 (RED II/III) — HVO from waste oils
Why is Bio-LNG negative? Bio-LNG made from manure captures methane that would otherwise escape from manure storage. The EU methodology credits this avoided methane, so producing and using manure-based Bio-LNG results in a net reduction of emissions.
CO₂ per shipment (freight forwarders)
When several shipments share one truck, the truck's CO₂ for the trip is allocated to each shipment by its share of tonne-kilometres:
Shipment CO₂ = Truck CO₂ × Shipment share
This follows the allocation principle of the GLEC Framework. Each shipment can be reported in its own scope (WTW or TTW), and results can be grouped per client.
Telematics data
Transport companies using Mapon can calculate from real data: CO2Calc reads the fuel used and the distance driven from the vehicle's CAN bus counters for the selected period and applies the same factors. Fuel type is detected for diesel and LNG vehicles; HVO and Bio-LNG can't be told apart from telematics and are chosen manually.
What is not covered
Electric vehicles, petrol, LPG and CNG are not calculated, because there is no single verified EU emission factor we could apply to them. Refrigeration units, empty-running allocation and hub emissions are not modelled separately — include empty kilometres in the distance if you want them counted.
Results are estimates based on the data you enter and the factors above. They are suitable for client reporting and internal tracking, but are not an audited or certified emissions statement.
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