AER - Annual Efficiency Ratio
Compute a ship's Annual Efficiency Ratio (AER) - total annual CO₂ divided by the product of deadweight and distance sailed. Used by Poseidon Principles signatories and the IMO CII regime.
Ship & voyage
Annual fuel consumption
One row per fuel type burned in the reporting year. CO₂ is computed from fuel mass × MEPC.364(79) Cf.
AER
2.373gCO₂ / (dwt·nm)
Total 7.8 kt CO₂.
Formula, assumptions, and limits
AER = Σⱼ (Fⱼ × Cfⱼ × 10⁶) / (DWT × Distance)
AER is numerically identical to the AER form of the CII Attained metric (MEPC.336(76)) for cargo ships that use DWT as the capacity basis. It's named separately because the Poseidon Principles use it as a standalone metric for climate alignment, independent of the IMO rating regime.