Lipid droplets store triacylglycerols (triglycerides) and sterol esters to regulate lipid and energy homeostasis. Triacylglycerol measurement is often performed during the investigation of lipid droplet formation and growth. This protocol describes a reliable method using a fluorometric lipid quantification kit to measure triacylglycerols extracted from HeLa cells, which were treated with oleic acid to trigger the formation of lipid droplets. The lipid quantification kit employs a lipid-binding molecule that emits bright fluorescence only when bound to extracted triacylglycerols, whose content can be quantified by a simple fluorescence readout.