HomeCalculatorsCII Rating - Carbon Intensity A to E grade

CII Rating - Carbon Intensity A to E grade

Enter a ship's attained CII (from your own reporting or the CII Attained calculator) and get the required CII and A–E rating per MEPC.337(76), MEPC.338(76), and MEPC.339(76).

IMOOperationalMEPC.339(76)

Ship & reporting period

Ship typeShip capacityDWTDeadweight - used for most cargo ships per MEPC.337(76).Reporting yearSelects the MEPC.338(76) annual reduction factor Z (5 % in 2023 rising to 11 % in 2026).

Your attained CII

From your own annual-reporting spreadsheet, a CII Attained calculation, or your DCS verifier's statement.

Attained CIIgCO₂ / (dwt·nm)Annual CO₂ in grams divided by (capacity × distance). The unit matches the capacity basis (DWT for most cargo ships, GT for passenger / ro-pax / cruise).

Required CII

3.792gCO₂ / (dwt·nm)

Reference line 4.167 × (1 − 9 %)

Attained / Required

0.844

15.6 % below required - better than target.

Rating

Major superior performance. No corrective action required.

Formula, rating boundaries, and consequences

Required CII is a reference line reduced by the year's Z factor:

a, c - ship-type-specific coefficients from MEPC.337(76) Table 1.
Z - annual reduction factor per MEPC.338(76): 5 % (2023), 7 % (2024), 9 % (2025), 11 % (2026).

Rating - compare the ratio Attained / Required to the four boundaries d₁ < d₂ < d₃ < d₄ from MEPC.339(76). Boundaries for the selected ship type are shown below; they differ by ship type.

Rating	Ratio range
A	≤ 0.86
B	0.86 < r ≤ 0.94
C	0.94 < r ≤ 1.06
D	1.06 < r ≤ 1.18
E	> 1.18

Consequences: A or B earns recognition and some port incentives. C is the compliant baseline. D for three consecutive years or a single E triggers a mandatory SEEMP Part III corrective action plan, reviewed by the flag administration before the next Statement of Compliance is issued.