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.

IMOOperationalAER

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\text{AER} = \frac{\sum_j F_j \cdot C_{f,j} \cdot 10^6}{\text{DWT} \cdot \text{Distance}}

Symbol	Meaning	Unit
$\text{AER}$	Annual Efficiency Ratio	g CO₂ / (dwt·nm)
$F_j$	Mass of fuel $j$ burned in the reporting year	t
$C_{f,j}$	CO₂ conversion factor for fuel $j$	t CO₂ / t fuel
$DWT$	Deadweight tonnage	t
$Distance$	Total distance sailed in the reporting year	nm
$10^6$	Unit conversion tonnes → grams

Source: Poseidon Principles - signatories' annual disclosure framework; IMO MEPC.336(76) - operational CII guidelines; IMO MEPC.364(79) - Cf fuel conversion factors

In short

Compute AER, the annual CO₂ intensity per deadweight-nautical-mile used by Poseidon Principles and the IMO operational CII regime.

Learn the theory BIMCO CII and Emissions Clauses