Cubic Capacity Correction (fcᵤbᵢc)
Chemical-tanker EEDI correction. High cargo-tank/DWT ratios mean DWT understates capacity; fcᵤbᵢc compensates so chemical carriers aren't unfairly penalised vs crude tankers.
Volume / DWT ratio
1.200
fcᵤbᵢc correction factor
1.000
No correction - ratio at or below 1.7 threshold.
Formula - MEPC.1/Circ.866
fcᵤbᵢc = max(1, (Cargo Volume / DWT) / 1.7) - indicative form
Chemical tankers are required to carry in specific tank arrangements (often 30+ tanks with coatings) that are heavy per cubic metre. A 50,000 DWT chemical tanker typically has 60,000 m³ of cargo capacity (ratio 1.2); a crude tanker of similar DWT might have 70,000 m³ (ratio 1.4). The fcᵤbᵢc correction makes the EEDI denominator more permissive when the ratio exceeds 1.7 - a threshold typical of parcel chemical carriers.
The exact formula varies by IMO circular revision; operators should use the current MEPC.1/Circ.866-series formula with their class society.