Estimate your vessel's IMO Carbon Intensity Indicator (CII) rating against the latest reduction factors set by MEPC.400(83), adopted April 2025. Enter operational data; see the rating you'd receive today, and what the same vessel would rate as the regulatory thresholds tighten toward 2030.
All fields update results live. Defaults represent a typical mid-size bulk carrier.
Based on the inputs at left. Updates as you type.
Under MEPC.347(78), the Ship Energy Efficiency Management Plan (SEEMP Part III) must contain an implementation plan demonstrating how required CII will be met for 2026–2028, with the revised plan amended and approved by 31 December 2025. The 2027 onwards regime tightens fast — a vessel rated C today may face D or E within 24 months.
Lex Dux LLP provides hands-on CII compliance strategy — from gap analysis through SEEMP Part III drafting to longer-term architectural compliance through the MZM Hybrid Protocol approach.
Marine Chief Engineer · Naval Architect · Inventor
Inventor of the Manus-Zim Modular (MZM) Hybrid Protocol — a ship design framework engineered specifically for IMO 2027 CII compliance through modular power generation and structural ballast redistribution. Author of four MEO certification reference books.
This tool provides an indicative CII rating estimate using IMO-published reference line coefficients (MEPC.353(78)), rating boundaries (MEPC.354(78)), and Z-factor reduction values from MEPC.400(83) adopted at MEPC 83 on 11 April 2025. Calculations use CO₂ emission factors from MARPOL Annex VI Appendix.
Actual CII verification by your Recognized Organization (RO) or Administration uses your verified IMO DCS data, applies any voyage adjustments and correction factors permitted under MEPC.355(78), and accounts for fuel-specific Lower Calorific Value (LCV) variations. The estimate produced here will not exactly match a verified attained CII but is generally within ±5% for routine vessel profiles.
This calculator does not address EEXI, GFI (GHG Fuel Intensity) under the forthcoming Net-Zero Framework, or regional regulations such as the EU ETS for shipping. For comprehensive compliance strategy, please contact Lex Dux LLP.
