# CII (/docs/regulations/cii)



The [International Maritime Organization](https://www.imo.org/)s *Maritime Environment Protection Committee* regulates requirements for general *Carbon Intensity* of a vessel.
The overview of related resolutions can be found on the [MARPOL Annex VI Overview Page](https://www.imo.org/en/ourwork/environment/pages/index-of-mepc-resolutions-and-guidelines-related-to-marpol-annex-vi.aspx).

The **Required annual operational CII** is a value specified in [MEPC.328(76) - Regulation 28](https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/Air%20pollution/MEPC.328%2876%29.pdf#page=47).

Emission+ calculates the [**required CII**](https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.353\(78\).pdf#page=4),
depending on the vessels ship type and capacity, together with its [**attained CII**](https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MEPCDocuments/MEPC.355\(78\).pdf#page=6).

## Attained CII Calculations [#attained-cii-calculations]

Emission+ calculates the **attained CII** and the resulting **rating**.

We automatically take care of:

* The **required CII** based on your vessel type and capacity.
* **Distance reductions** for reductible voyages.
* Exemptions for applicable **Ship to Ship Transfers**.
* Reductions for consumptions related to **electrical energy**.
* Reductions related to consumptions for **cargo boilers**.
* Exemptions regarding **Ice Voyages**.
* Exemptions regarding **Emergencies**.
* Reductions resulting from **Bio-Fuels**.