We are using the real-world observations of cattle enteric methane emissions to evaluate current prediction equations methane emissions. Direct measurement is not possible for all cattle methane emissions, so prediction of methane plays an important role in emission inventories for at different scales (operations, companies/supply chains, national). However, models need to be evaluated against real observations from cattle, and improved where necessary. We are building a broad dataset from our observations of cattle across production environments and diets to evaluate models.