This paper sets out the approach that will be used to convert energy measured under the AS/NZS 4474.1 test standard to estimate the likely energy consumption under the International Electrotechnical Commission 62552-3 test standard. This approach will form the basis on which the GEMS Regulator will assess whether household refrigerating appliances that have been registered under the Greenhouse and Energy Minimum Standards (Household Refrigerating Appliances) Determination 2012 will meet MEPS 2021 levels that will come into effect on 15 August 2021. The paper was first published on 21 October 2018 and later revised in July 2020 to clarify some variables. The methodology for calculating MEPS 2021 and projected MEPS energy consumption (PMEC) remains unchanged, while material that does not pertain to either (such as labelling references) has been removed.