CII Online Calculator Guidance

On June 2021, the IMO adopted some new CO2 mandatory regulations applicable to existing ships. The Energy Efficiency Existing Ship Index (EEXI) addressing the technical efficiency of ships, the Carbon Intensity Indicator (CII) rating scheme addressing the operational efficiency, and the enhanced Ship Energy Efficiency Management Plan (SEEMP) addressing the management system.

This online service calculates the carbon intensity indicator rating based on the latest IMO published guidelines.

Since entering the wrong data into this calculator can lead to an incorrect answer, please make sure that the information is entered correctly. For this reason, it may be helpful to read the current guidance.

Note: All fields must be filled by certified or approved documents.

Wrong Entries = Wrong Results

DCS Calendar Year

This field refers to the calendar year according to the fuel consumption report was reported to the IMO. This year can be chosen from 2022 to 2030.

Ship Type

For the following ship types of 5000 GT & above engaged in international voyages, the attained CII should be calculated:

  1. Bulk carrier
  2. Gas carrier (LPG carrier)
  3. LNG carrier
  4. Tanker
  5. Containership
  6. General cargo ship
  7. Refrigerated cargo carrier
  8. Combination carrier
  9. Ro-ro cargo ships (Vehicle carrier)
  10. Ro-ro cargo ship
  11. Ro-ro passenger ship
  12. Cruise passenger ship

Each of these ship types is defined as follows:

Bulk carrier means a ship which is intended primarily to carry dry cargo in bulk, including such types as ore carriers as defined in regulation 1 of chapter XII of the International Convention for the Safety of Life at Sea (SOLAS), 1974, (as amended) but excluding combination carriers.

Combination carrier means a ship designed to load 100% deadweight with both liquid and dry cargo in bulk.

Containership means a ship designed exclusively for the carriage of containers in holds and on deck.

Cruise passenger ship in relation to chapter 4 means a passenger ship not having a cargo deck, designed exclusively for commercial transportation of passengers in overnight accommodations on a sea voyage.

Gas carrier in relation to chapter 4 means a cargo ship, other than an LNG carrier as defined in paragraph 2.16 of this regulation, constructed or adapted and used for the carriage in bulk of any liquefied gas.

General cargo ship means a ship with a multi-deck or single deck hull designed primarily for the carriage of general cargo. This definition excludes specialized dry cargo ships, which are not included in the calculation of reference lines for general cargo ships, namely livestock carrier, barge carrier, heavy load carrier, yacht carrier, nuclear fuel carrier.

LNG carrier in relation to chapter 4 of this Annex means a cargo ship constructed or adapted and used for the carriage in bulk of liquefied natural gas (LNG).

Tanker means an oil tanker as defined in regulation 1 of Annex I of the present Convention or a chemical tanker or an NLS tanker as defined in regulation 1 of Annex II of the present Convention.

Refrigerated cargo carrier means a ship designed exclusively for the carriage of refrigerated cargoes in holds.

Ro-ro cargo ship means a ship designed for the carriage of roll-on-roll-off cargo transportation units.

Ro-ro cargo ship (vehicle carrier) means a multi-deck roll-on-roll-off cargo ship designed for the carriage of empty cars and trucks.

Ro-ro passenger ship means a passenger ship with roll-on-roll-off cargo spaces.

Due to differences in the input data of different ship types, please be careful in choosing this field.

Ice classed ships:

If the ship is ice-class click on check box then select one of the following items:

  1. IC
  2. ID
  3. IA
  4. IA Super

For further information on approximate correspondence between ice-classes, see HELCOM Recommendation 25/7 (HELCOM Recommendation 25/7 may be found at www.helcom.fi)

Voluntary structural enhancements

Structural and/or additional class notations such as, but not limited to, "strengthened for discharge with grabs" and "strengthened bottom for loading/unloading aground", which result in a loss of deadweight of the ship, are also seen as examples of "voluntary structural enhancements".

In each case, two sets of structural plans of the ship should be submitted to the verifier for assessment. One set for the ship without voluntary structural enhancement; the other set for the same ship with voluntary structural enhancement (alternatively, one set of structural plans of the reference design with annotations of voluntary structural enhancement should also be acceptable). Both sets of structural plans should comply with the applicable regulations for the ship type and intended trade.

Please click on check box, if needed and input requested data.

Distance travelled

Represents the total distance travelled (in nautical miles), as reported under IMO DCS.

Distance travelled which may be deducted

Represents distance travelled (in nautical miles) for voyage periods which may be deducted from CII calculation in case the ship encounters one of the following situations:

  1. scenarios specified in regulation 3.1 of MARPOL Annex VI, which may endanger safe navigation of a ship;
  2. sailing in ice conditions, which means sailing of an ice-classed ship in a sea area within the ice edge

Voyage adjustment

A voyage adjustment deducts relevant fuel consumption, as well as the associated distance travelled from the calculation of attained CII for a defined period subject to certain threshold conditions being met.

Please click on check box, if needed.

Correction factor

A correction factor means a factor in the numerator or denominator of the CII formula which adjusts the calculation of the attained CII.

Please click on check box, if needed.

STS Operation

A tanker should be considered in Ship-to-Ship (STS) operation when operating in accordance with regulation 41.2 of MARPOL Annex I and applying the best practices in accordance with the OCIMF Ship to Ship Transfer Guide for Petroleum, Chemical and Liquefied Gases. For the purpose of this calculator, a tanker is engaged in an STS voyage if a voyage between cargo loading and cargo discharging locations, or a voyage between cargo discharging and cargo loading locations does not exceed 600 nautical miles and the time for each of these voyages (which does not include port or discharge time) is limited to 72 hours.

Shuttle Tanker

A Shuttle Tanker is a tanker which is equipped with Dynamic Positioning and specialized cargo handling equipment making them capable of loading crude oil at offshore installations.

Self-unloading bulk carrier

A self-unloading bulk carrier is a bulk carrier with an onboard cargo handling system that is utilized to discharge dry bulk cargo via a boom conveyor or shipboard cargo pipeline equipment.

Refrigerated container

A refrigerated container is an intermodal shipping container that is refrigerated (including chilled and frozen containers) or heated for the transportation of temperature sensitive cargo, which will receive its power from the ship’s power supply.

𝐢𝐹

𝐢𝐹𝑗 represents the fuel mass to CO2 mass conversion factor for fuel type 𝑗, in line with those specified in the 2018 Guidelines on the method of calculation of the attained EEDI for new ships (resolution MEPC.308(73) as amended by resolution MEPC.322(74)), as may be further amended;

𝐹𝐢𝑗

𝐹𝐢𝑗 is the total mass of consumed fuel of type 𝑗 in the calendar year, as reported under IMO DCS.

𝐹𝐢 π‘£π‘œπ‘¦π‘Žπ‘”π‘’, 𝑗

𝐹𝐢 π‘£π‘œπ‘¦π‘Žπ‘”π‘’, 𝑗 is the mass (in grams) of fuel of type 𝑗, consumed in voyage periods during the calendar year which may be deducted in case the ship encounters one of the following situations:

  1. scenarios specified in regulation 3.1 of MARPOL Annex VI, which may endanger safe navigation of a ship;
  2. sailing in ice conditions, which means sailing of an ice-classed ship in a sea area within the ice edge

SFC

SFC is the certified specific fuel consumption, measured in g/kWh, of the engines or steam turbines.

𝑭π‘ͺ π’†π’π’†π’„π’•π’“π’Šπ’„π’‚π’, 𝒋

𝑭π‘ͺ π’†π’π’†π’„π’•π’“π’Šπ’„π’‚π’, 𝒋 is the mass (in grams) of fuel of type 𝑗, consumed for production of electrical power during the calendar year which may be deducted from the calculation of the attained CII for the following purposes:

  1. Electrical consumption of refrigerated containers (on all ships where they are carried)
  2. Electrical consumption of cargo cooling/liquefaction systems on gas carriers and LNG Carriers.
  3. Electrical consumption of discharge pumps on tankers

𝐹𝐢 π΅π‘œπ‘–π‘™π‘’π‘Ÿ, 𝑗

The parameter 𝐹𝐢 π΅π‘œπ‘–π‘™π‘’π‘Ÿ, 𝑗 is the mass (in grams) of fuel of type 𝑗, consumed by the oil fired boiler during the calendar year which may be deducted from the calculation of the attained CII, for the purposes of cargo heating and cargo discharge on tankers.

𝐹𝐢 π‘œπ‘‘β„Žπ‘’π‘Ÿπ‘ , 𝑗

The parameter 𝐹𝐢 π‘œπ‘‘β„Žπ‘’π‘Ÿπ‘ , 𝑗 is the mass (in grams) of fuel of type 𝑗, consumed by standalone engine driven cargo pumps during discharge operations on tankers which may be deducted from the calculation of the attained CII.

Reefer KWh is measured on the vessel by the kWh meter counter on the vessel.

SFOC represents the specific fuel consumption in g/kWh as a weighted average of the engines used to provide the electrical power, as per the EEDI/EEXI Technical File or the NOx Technical File. In the case of ships without a Technical File, a default value of 175 g/kWh for 2 stroke engines and 200 g/kWh for 4 stroke engines may be applied. In the case of waste heat recovery systems as defined under Category C1 in MEPC.1/Circ.896 the SFOC to be used will be at the discretion of the Administration.

Reefer_days sea represents the number of in-use reefer-days over the declared period and may be derived using the number of reefer containers as recorded in the BAPLIE file multiplied by the number of days at sea.

Days Port represents number of days in port.

π‘π‘œ 𝑐 Arrival represents number of reefer containers on arrival.

No C Departure represents number of reefer containers at departure.

In all cases, the actual number of in-use reefers carried is documented in the BAPLIE file.

Note that ship reefer kWh consumption should not include consumption during voyage adjustment periods.