RS introduces ship’s carbon intensity calculation tool


Russian Maritime Register of Shipping (RS) has developed an online calculator for shipowners to estimate ship’s Carbon Intensity Indicator (CII) values based on the quantity of fuel oil consumed and the distance traveled per calendar year. The tool also enables to determine the ship’s operational carbon intensity rating.

The requirements to calculate the attained and the required operational carbon intensity indicators were introduced by the MARPOL Annex VI amendments adopted at the 76th session of the IMO’s Marine Environment Protection Committee (MEPC 76) and become mandatory from January 1, 2023. After 2023, the annual calculation is required for certain types of 5000 GT and above ships engaged in international voyages. The shipowner is responsible for the calculation and may engage a competent organization to perform it.

Based on the attained CII and fuel oil consumption data the ship’s flag state maritime administration or its recognized organization rates the operational carbon intensity according to the А-E scale with A being the major superior grade. A low-rated ship (D for three consecutive years, or E) is required to develop a corrective action plan being part of the enhanced Ship Energy Efficiency Management Plan (SEEMP). The SEEMP shall also include an implementation plan documenting how the required annual operational CII will be achieved during the next three years starting from 2023.

RS recommends the shipowners to determine the CII and the associated operational carbon intensity rating based on the existing fuel oil consumption data of 2019-2021 and to take the top priority corrective actions for a smooth transition to the new requirements compliance.

The calculator is accessible for the ships falling under the new requirements via RS Members Area at

This new online tool offers preliminary calculations of the CII values and does not cancel the obligation of the shipowner to provide a detailed calculation to the maritime administration or a recognized organization. The report generated does not constitute the regulatory statement of compliance with the IMO requirements.

The RS new MARPOL Annex VI services currently cover the review of the EEXI technical file, ship’s Onboard Management Manual (OMM) for shaft / engine power limitation system and the enhanced SEEMP as well as rating the ship’s carbon intensity.

General procedure of СII requirements implementation