GFI Attained - WtW Intensity from Fuel Mix
Compute the well-to-wake GHG fuel intensity (Attained GFI) of a ship's annual fuel mix, in g CO₂e/MJ, using the IMO LCA Guidelines default values from MEPC.391(82). The Attained GFI feeds the IMO Net-Zero Framework compliance check.
Annual fuel mix
One row per fuel burned in the reporting year. Mass is in tonnes; the calculator looks up the LHV and well-to-wake intensity from the MEPC.391(82) default tables.
Formula, default values, and limits
Weighted average well-to-wake GHG fuel intensity, with weights given by the energy contribution of each fuel. The result is the input to the GFI compliance calculator and to the IMO Net-Zero Framework Required GFI check.
Default well-to-wake values (MEPC.391(82) Table 1)
| Fuel pathway | LHV (MJ/kg) | WtW (g CO₂e/MJ) |
|---|---|---|
| HFO (residual) | 40.2 | 90.5 |
| VLSFO 0.50% | 40.5 | 89.5 |
| MGO (distillate) | 42.7 | 88.3 |
| LNG - 4-stroke medium-speed Otto | 49.1 | 86.9 |
| LNG - 2-stroke slow-speed Otto | 49.1 | 80.7 |
| LNG - 2-stroke Diesel cycle | 49.1 | 75.8 |
| B30 biofuel blend (UCO) | 41.9 | 63.2 |
| B100 biodiesel (UCO, net biogenic) | 38.0 | 5.0 |
| Bio-MGO (UCO, net biogenic) | 42.7 | 4.8 |
| Bio-LNG (waste, net biogenic) | 49.1 | 19.7 |
| Methanol (grey, fossil) | 19.9 | 100.0 |
| Methanol (green e-fuel) | 19.9 | 5.5 |
| Ammonia (grey, fossil) | 18.6 | 127.0 |
| Ammonia (blue, with CCS) | 18.6 | 60.0 |
| Ammonia (green e-fuel) | 18.6 | 12.0 |
| Hydrogen (green e-fuel) | 120.0 | 5.0 |
For ship-specific values certified under the IMO LCA Guidelines (MEPC.376(80)) audit framework, override the defaults at the fuel-supply contract stage; the calculator uses defaults until certified values are entered into the IMO DCS.