CII for ro-pax ships: required CII, rating boundaries and calculator
The carbon intensity a ro-ro passenger ship must reach each year from 2023 to 2030, by size, with the IMO reference line and the A to E boundaries. Try it on your own ship below.
Updated 2026-10-20
Calculate
Required CII for ro-pax ships, 2023 to 2030
| Size | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 |
|---|---|---|---|---|---|---|---|---|
| 15,000 GT | 23.05 | 22.57 | 22.08 | 21.60 | 20.96 | 20.32 | 19.69 | 19.05 |
| 35,000 GT | 15.61 | 15.28 | 14.95 | 14.63 | 14.19 | 13.76 | 13.33 | 12.90 |
| 60,000 GT | 12.18 | 11.93 | 11.67 | 11.41 | 11.08 | 10.74 | 10.40 | 10.07 |
g CO₂ per GT-nautical mile. Required CII = (1 − Z/100) × a × capacity−c, with Z from 5% in 2023 to 21.5% in 2030 (resolution MEPC.338(76) as amended).
The reference line
Capacity is gross tonnage. Capacity basis: gross tonnage (G2, resolution MEPC.353(78)).
Rating boundaries in 2026
| Size | A up to | B up to | C up to | D up to | E |
|---|---|---|---|---|---|
| 15,000 GT | 16.41 | 19.87 | 24.62 | 28.08 | above |
| 35,000 GT | 11.12 | 13.46 | 16.67 | 19.01 | above |
| 60,000 GT | 8.67 | 10.50 | 13.01 | 14.84 | above |
Boundaries are the required CII multiplied by 0.76, 0.92, 1.14, 1.30 (G4, resolution MEPC.354(78)).
Rated D or E?
A ship rated D three years running, or E once, needs a corrective action plan in its SEEMP Part III. How the plan is prepared, or check what EU ETS and FuelEU cost the same ship in the EU ETS and FuelEU calculators.
Questions
What is the required CII for a 35,000 GT ro-ro passenger ship in 2027?
14.19 g CO₂ per GT-nautical mile: the reference value of 16.43 reduced by 13.625%.
Which capacity is used for the CII of a ro-ro passenger ship?
Gross tonnage. Capacity is gross tonnage.
What are the CII rating boundaries for ro-pax ships?
The required CII multiplied by 0.76, 0.92, 1.14 and 1.30. For a 35,000 GT ship in 2026 a CII up to 11.12 is A, up to 13.46 B, up to 16.67 C, up to 19.01 D, and above that E.
How many ro-pax ships report to the EU MRV register?
426 in the reporting period 2025, with a median of 29,890 tonnes of CO₂ each.
EU ETS, FuelEU, CII and UK ETS for each ship, from the public register or your own data.