Documentation Index
Fetch the complete documentation index at: https://docs.appliedaifoundation.org/llms.txt
Use this file to discover all available pages before exploring further.
This page documents the exact formulas and constants used in src/lib/utils/ciiCalculator.ts.
Reference CII
CII_ref = a × Capacity^(-c)
| Ship type | Capacity | a | c |
|---|
| Container | DWT | 1,984 | 0.489 |
| Bulk Carrier | DWT | 4,745 | 0.622 |
| Tanker | DWT | 5,247 | 0.610 |
| Gas Carrier | DWT | 14,405 | 0.807 |
| LNG Carrier | DWT | 9,827 | 0.718 |
| General Cargo | DWT | 588 | 0.388 |
| Ro-Ro | DWT | 2,023 | 0.460 |
| Cruise | GT | 930 | 0.383 |
TANKER, “Car Carrier” → RO_RO).
Required CII
Required CII = Reference CII × (1 − reduction_factor)
| Year | Reduction |
|---|
| 2019 | 0% (baseline) |
| 2020 | 1% |
| 2021 | 2% |
| 2022 | 3% |
| 2023 | 5% |
| 2024 | 7% |
| 2025 | 9% |
| 2026 | 11% |
| 2027 | 13% |
| 2028 | 15% |
| 2029 | 17% |
| 2030 | 19% |
| 2031+ | 19% + 2% per year (extrapolation) |
Attained CII
Attained CII = (Total CO₂ in grams) / (Capacity × Distance NM)
× 1,000,000).
Rating boundaries
Ratings A–E are determined by multiplying the Required CII by ship-type-specific d-factors (boundary multipliers from MEPC.354(78)):
| Ship type | d1 (A) | d2 (B) | d3 (C) | d4 (D) |
|---|
| Container | 0.83 | 0.94 | 1.07 | 1.19 |
| Bulk Carrier | 0.86 | 0.94 | 1.06 | 1.18 |
| Tanker | 0.82 | 0.93 | 1.08 | 1.28 |
| Gas Carrier | 0.81 | 0.91 | 1.12 | 1.44 |
| LNG Carrier | 0.89 | 0.98 | 1.06 | 1.13 |
| General Cargo | 0.83 | 0.94 | 1.06 | 1.19 |
| Ro-Ro | 0.66 | 0.90 | 1.11 | 1.37 |
| Cruise | 0.87 | 0.95 | 1.06 | 1.16 |
Rating boundary X = Required CII × d_X
- Attained ≤ d1 × Required → A
- Attained ≤ d2 × Required → B
- Attained ≤ d3 × Required → C (this is the compliance threshold)
- Attained ≤ d4 × Required → D
- Otherwise → E
Compliance margin
Compliance margin = Required CII − Attained CII
COMPLIANT if Attained ≤ Required, otherwise NON_COMPLIANT.
Implementation
src/lib/utils/ciiCalculator.ts — exports calculateCII, calculateCIISafe, calculateCIIWithReeferCorrection, and calculateCIIWithReeferCorrectionSafe.
Safe variants return null instead of throwing when inputs are missing — used throughout the app where data quality varies by vessel.
Reference
