Attained CII • Required CII • IMO A-E Rating • 2023-2030 Reduction Path • C-Rating Headroom • Fuel / CO2 Improvement Target
CII Rating Calculator for Ships
Calculate attained annual operational CII, the required CII for the selected reporting year and the IMO A to E rating using ship type, capacity, annual distance and fuel or verified CO2 data. Advanced mode adds multiple fuels, verified CII adjustments, rating-history context, 2030 outlook and operational stress scenarios.
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Need multiple fuels, verified correction factors, rating history or stress cases? Click Advanced above.Simple uses one fuel line or a verified annual CO2 override and applies the official ship-type reference line, reporting-year reduction factor and IMO rating-boundary vectors.Ship & Reporting Year
DWT used by the CII framework for this ship type.
nm/year. Use total IMO DCS distance for CII purposes.
Annual Fuel & CO2
MT/year.
tCO2 per MT fuel. Editable.
tCO2/year. If entered, replaces fuel-derived CO2.
Planning Scenario
%. Negative means lower CO2.
%. Used only for the planning scenario result.
Verified CII Basis
nm/year before any verified adjusted-distance override.
Use only if the verified CII calculation applies an approved adjusted denominator.
tCO2 deducted only when supported by the verified CII/G5 basis.
Fuel Mix
Use fuel-specific mass and CO2 factors. The conversion factors below are editable planning defaults and should be replaced by the factor applicable to the actual fuel/documentary basis.
| Use | Fuel type | Consumed MT | CF tCO2/MT |
|---|
Rating History & SEEMP Context
Operational Stress Cases
Stress annual CO2 and distance without changing the official ship-type reference line. Labels are categorical so no vessel/project identifiers are required.
| Use | Scenario | CO2 change % | Distance change % |
|---|
CII Readiness Checks
Compliance boundary: this is a planning and decision-support calculator. It does not replace the verified attained annual operational CII, Statement of Compliance, SEEMP Part III, Administration / recognized-organization verification, or the detailed application of eligible CII correction factors and voyage adjustments. Advanced manual adjustment fields should only be used when the underlying verified method supports them.