Greenhouse gas (GHG) emissions significantly impact climate change, with livestock contributing a substantial share. Livestock emissions, including methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2), constitute 14.5% of all human-induced GHG emissions. Small ruminants, such as sheep and goats, contribute approximately 6.7% to total livestock emissions. Accurate estimation of GHG emissions is crucial for inventory purposes and emission reduction strategies. Methane conversion rate (Ym) plays a pivotal role in quantifying enteric CH4 emissions, representing the proportion of the animal's gross energy intake converted to CH4 energy. This study emphasizes the significance of Ym and its continuous revision to ensure reliable regional and national GHG emission inventories. The values of Ym ideally require direct measurements of CH4 emission, dietary intake, and digestibility. Accurate determination of Ym is vital for setting achievable targets to reduce enteric methane emissions. Understanding and improving Ym estimation procedures are essential steps toward mitigating the environmental impact of livestock-related GHG emissions.