EEXI calculator: attained against required
Is a ship’s EEXI below the limit for its type and size? Enter the attained value from its technical file, or the engine power and speed to estimate it.
Updated 2026-10-28
Check a ship
How the check works
The required EEXI is the EEDI reference line for the ship type, a × b−c, reduced by the factor Y for its type and size. Bulk carriers cap b at 279,000 dwt; vehicle carriers use their deadweight-to-gross-tonnage ratio, so they need both; ro-ro and ro-pax ships use the phase-2 reference lines (resolution MEPC.328(76), Regulations 24 and 25, checked line by line).
Without an attained value, it is estimated with the simplified EEDI formula: 75% of MCR, the default fuel consumption of a slow-speed main engine and auxiliaries, the fuel’s carbon factor, the capacity and the reference speed. The result is marked indicative.
Questions
What is the EEXI?
The Energy Efficiency Existing Ship Index: a design measure of the CO₂ a ship emits per tonne-mile at a reference speed and 75% of its engine power (or of its limited power). It has applied to existing ships of 400 GT and above since 1 January 2023.
How is the required EEXI calculated?
From the EEDI reference line for the ship type and size, a × b^-c (MARPOL Annex VI Regulation 24, Table 2), reduced by the type's factor Y (Regulation 25, Table 3).
What if the attained EEXI is above the required value?
The usual fix is an engine or shaft power limitation (EPL/ShaPoLi), sometimes with energy-saving devices. The new value is approved in a revised EEXI technical file.
Is this estimate good enough for the technical file?
No. It is a first check. The EEXI technical file uses the ship's own sea-trial or model-test speed-power data and test-bed SFOC, and is verified by the Administration or its recognised organisation.
Where does the register's EEXI come from?
THETIS-MRV publishes each ship's technical efficiency (EEXI, EEDI or EIV). For a ship in the register, the app compares it with the required value automatically.
EU ETS, FuelEU, CII and UK ETS for each ship, from the public register or your own data.