Free Tool · No Login

LNG Boil-Off Calculator

Actual BOR vs guarantee BOR, cargo loss in m³ and USD, forced BOG dispatch. Moss / GTT NO96 / Mark III / Mark III Flex containment systems supported.

GIIGNL Custody Transfer

Age adjustment

Guarantee exposure

Voyage data

Free · No Login

Containment system

Cargo Volume (m³ LNG)

Voyage Days (laden)

Ballast Days

Vessel Age (years)

Guarantee BOR (%/day)

Actual Measured BOR (%/day)

LNG Price ($/MMBtu)

Propulsion Fuel (MT LNG/day)

Engine · BOG type

–

effective BOR · laden voyage

–

Cargo Loss

–

m³ LNG

Loss Value

–

USD

Natural BOG

–

MT/day

Forced BOG

–

MT/day

Track BOR + guarantee exposure across your LNG fleet — VEMO logs daily BOR per vessel + flags breaches.

Start Free Trial →

Typical BOR by containment

Guarantee values from shipyard delivery specification. Actual BOR degrades ~0.005-0.015%/day per 5 years of vessel age.

Moss Spherical

0.10-0.15

%/day laden

GTT NO96

0.10-0.13

%/day laden

GTT Mark III

0.08-0.11

%/day laden

Mark III Flex

0.07-0.10

%/day laden

Mark III Flex+

0.05-0.08

%/day laden

NO96 GW

0.08-0.11

%/day laden

Frequently asked questions

What is LNG boil-off rate (BOR)?

Percentage of an LNG cargo that evaporates per day due to heat ingress. Moss 0.10-0.15%/day, NO96 0.10-0.13%/day, Mark III 0.08-0.11%/day, Mark III Flex 0.07-0.10%/day. Ballast BOR typically 30-50% higher due to cargo heel warming faster.

What is guarantee BOR?

Maximum boil-off rate warranted by the shipyard at delivery. Exceeding guarantee triggers commercial penalties in charter parties and cargo-loss claims against the operator.

What is forced BOG?

Additional LNG deliberately vaporized when natural boil-off is insufficient to meet propulsion demand. Vaporizer inefficiency ≈15-25% means forced BOG consumes more fuel than natural BOG per MJ of propulsion energy.

How does BOR change with age?

BOR typically increases 0.005-0.015%/day per 5-year interval due to insulation degradation, thermal bridges, and cargo containment ageing. A 15-year NO96 guaranteed at 0.13%/day may run at 0.16-0.18%/day in service.