Ro-Ro vs Road Emissions Calculator
Compare the carbon footprint of an all-road haul against a combined road + Ro-Ro routing for the same shipment. Built on GLEC Framework v3.2 factors on a well-to-wheel basis.
Enter the lane distance from your carrier's schedule. We do not estimate it: a Ro-Ro route through the Dardanelles, the Aegean and the Adriatic cannot be modelled by straight-line distance without a large error.
Enter cargo weight and at least one distance.
Methodology and sources
Why a dedicated Ro-Ro calculator?
Most freight emission tools offer a single "sea" factor. That factor is derived from container shipping, which is far more efficient per tonne-kilometre than roll-on/roll-off traffic: a Ro-Ro vessel carries trailers and rolling cargo, so a large share of the hold is unavoidably air. Applying a container factor to a Ro-Ro leg understates its emissions substantially. Smart Freight Centre and ECG published a harmonised, ISO 14083-aligned methodology for Ro-Ro greenhouse gas accounting precisely because of this gap — but until now it existed as guidance, not as a tool you could use on a shipment.
How the calculation works
Every leg is calculated with the tonne-kilometre method: emissions in kilograms of CO₂e equal cargo weight in tonnes, multiplied by leg distance in kilometres, multiplied by the emission intensity of that leg in grams per tonne-kilometre, divided by one thousand. The combined route is the sum of its three legs — pre-carriage by road, the Ro-Ro sea leg, and on-carriage by road — and is compared against the all-road alternative for the same shipment.
Which factors are used
Road legs use 86 g CO₂e/tonne-km (articulated truck, well-to-wheel). Ro-Ro legs use the GLEC Framework v3.2 values for Ro-Ro vessels on heavy fuel oil, shown in the table below. All values are well-to-wheel (WTW): they include the emissions of producing and distributing the fuel, not only what leaves the funnel. The column applied in the calculator is the one already adjusted by the 15% distance adjustment factor, in line with GLEC practice.
Why we do not estimate the sea distance
A Ro-Ro service between Türkiye and Europe passes the Dardanelles, crosses the Aegean, rounds Greece and runs up the Adriatic. Straight-line distance between the two ports bears little relation to the distance actually sailed, and applying a fixed detour multiplier — the usual shortcut — produces a large error on exactly this corridor. Carriers publish their lane distances, so the honest option is to ask for the real figure rather than manufacture one.
What the result is, and is not
The output is a Tier-1 estimate suitable for comparing routing options and for the shipment-level reporting customers increasingly request under CBAM. It is not a carrier-specific figure: a given operator's actual intensity depends on vessel, fuel, load factor and speed, and can differ materially from the default. When a counterparty requires audited numbers, ask your carrier for their vessel-specific intensity and substitute it.
Ro-Ro emission factors (GLEC v3.2)
| Vessel size | WTT | TTW | WTW | WTW +15% DAF |
|---|---|---|---|---|
| 15,000+ dwt | 2.9 | 16.5 | 19.5 | 22.4 |
| 10,000–14,999 dwt | 5.6 | 31.3 | 36.9 | 42.5 |
| 5,000–9,999 dwt | 6.7 | 37.7 | 44.4 | 51.0 |
| 0–4,999 dwt | 30.7 | 172.2 | 202.9 | 233.4 |
Unit: g CO₂e per tonne-kilometre. Ro-Ro vessels on heavy fuel oil (HFO). Source: GLEC Framework v3.2, Table 17 — Sea transport emission intensity values, non-container vessels. Published by Smart Freight Centre.
86 g CO₂e/tonne-km — articulated truck, well-to-wheel. Same value as our general freight CO₂ calculator, so results are directly comparable.
Frequently asked questions
How are Ro-Ro emissions calculated?
With the tonne-kilometre method defined by ISO 14083: emissions in kg CO₂e equal cargo weight in tonnes multiplied by leg distance in kilometres multiplied by the emission intensity of that leg in grams per tonne-kilometre, divided by one thousand. The combined route sums three legs — pre-carriage by road, the Ro-Ro sea leg and on-carriage by road.
Which emission factor does this calculator use for Ro-Ro?
The GLEC Framework v3.2 values for Ro-Ro vessels running on heavy fuel oil, Table 17. The default is 22.4 g CO₂e per tonne-kilometre for vessels of 15,000 dwt and above, which is the well-to-wheel figure including the 15% distance adjustment factor. Smaller vessel classes are selectable: 42.5, 51.0 and 233.4 g per tonne-kilometre.
Why not use the generic sea freight factor?
Generic sea factors are derived from container shipping, which is far more efficient per tonne-kilometre. A Ro-Ro vessel carries trailers and rolling cargo, so a large share of the hold is unavoidably air. Applying a container factor to a Ro-Ro leg understates its emissions substantially, which is why Smart Freight Centre and ECG published a separate ISO 14083-aligned methodology for Ro-Ro.
Why do I have to enter the sea distance myself?
A Ro-Ro service between Türkiye and Europe passes the Dardanelles, crosses the Aegean, rounds Greece and runs up the Adriatic. Straight-line distance between the ports bears little relation to the distance actually sailed, and a fixed detour multiplier produces a large error on this corridor. Carriers publish their lane distances, so we ask for the real figure rather than manufacture one.
Is the result good enough for CBAM or customer reporting?
It is a Tier-1 estimate suitable for comparing routing options and for the shipment-level reporting customers increasingly request. It is not a carrier-specific figure: actual intensity depends on vessel, fuel, load factor and speed. When a counterparty requires audited numbers, ask your carrier for their vessel-specific intensity and use that instead.