As crude oil prices rise in everyday life, the need to develop economically attractive alternative fuels increases. Biodiesel produced from used cooking oil is an example of replacement material. This paper involves clear idea and view about production of biodiesel from used cooking oil, which was obtained from various domestic sources . Methyle alcohol, with potassium hydroxide as a catalyst, reacts with used oil in a transesterification reaction to produce fatty acid methyl ester (FAME) with glycerol as a byproduct. The characteristics of our sample including density, viscosity, and heat of combustion are tested and contrasted to those of petrodiesel, making the product an integral biofuel. The paper will also involve blending or mixing biodiesel with petrodiesel and comparing their characteristics . The target of this paper is to utilize used cooking oil to transform it into biodiesel, as well as utilize glycerol for other purposes, such as soap making.