Squander cooking oils (WCO), which contain a lot of free unsaturated fats delivered in eateries, are gathered by the natural assurance office in many parts of the world and ought to be arranged reasonably. Because of the high cost of the new vegetable oil, squander cooking oil pulled in specialist to deliver bio-diesel from waste cooking oil since it is accessible with moderately shabby cost. In this venture paper, the Trans esterification of waste cooking oil with methanol and in addition the fundamental employments of the unsaturated fat methyl esters is looked into. The cooking oil was trans esterified with methanol utilizing potassium hydroxide as impetus to acquire bio-diesel by Magnetic Stirrer creation method was done. Comes about which acquired are altogether similar to immaculate diesel and gives preferable execution over routine diesel fuel.