Carbon Intensity Indicator (CII) Calculator For Ships

CII ratings (Carbon Intensity Indicator) aim to make the carbon intensity rating of any given ship easy to understand, transparent, and standardised.

Rating System

By implementing regulatory guidelines from the International Maritime Organisation (IMO), the Carbon Intensity Indicator (CII) of a ship can be calculated using a standardised methodology in a simple-to-understand range A to E:

A (CII below the Superior Boundary)
B (CII above the Superior Boundary and below the Lower Boundary)
C (CII between the Lower Boundary and the Upper Boundary)
D (CII above the Upper Boundary and below the Inferior Boundary)
E (CII above the Inferior Boundary)

Forecasting and Backcasting

The app generates a multi-year backcast & forecast of the ship's CII rating. This information can help ship owners identify when they will need to take action to bring their vessels inline with the International Maritime Organization's mandatory MARPOL Annex VI measures, enforced from January 2023 onwards.

Made For Humans. Digitised For Computers. Transparent Methodology.

Available through our online calculator tool or through a developer API. The full methodology is publicly available for review.

Try it out Review methodology

Follows IMO Standardized Regulations

Our implementation is aligned with IMO specifications required to adhere to MARPOL Annex VI regulatory measures, including MEPC.339(76), MEPC.364(79), and MEPC.337(76), and ISO standard 8217.

Review standards ↗

Open Source

Our underlying software is open source, published on GitHub, available for all parties to independently review.

C# version ↗ Python version ↗