This report is the deliverable for Milestones 1.3.1 and 2.2.1 of the FEnEx CRC’s Commonwealth Grant Agreement. The generation of boil‐off gas (BOG) is an unavoidable result of the cryogenic storage of liquefied natural gas (LNG) or liquid hydrogen (LH2) due to heat ingress into the storage tanks. Quantifying the amount of BOG that will be generated in a given amount of time is essential for engineering design calculations, assessing the cost of transport and storage, and optimising the economics of particular supply chain and delivery systems. However, BOG generation rates depend on many factors including details of the storage tank volume, geometry and construction materials as well as the level, pressure and temperature profile of the stored cryogenic liquid. Even for the well‐established LNG industry, the methods used to estimate BOG rates in large carrier ships is entirely empirical and specific to the particular vessel. Given the lower temperatures and higher costs associated with liquid hydrogen production and storage, reliably calculating BOG rates for prospective LH2 storage and transport systems is even more important.