In converting different vegetable oils for the respective esters, at a minimum reaction temperature and faster rate of the fatty acids, the catalyst plays a very important role which can be changed into fatty acid esters (FAME), also known as biodiesel by transesterification reaction with methanol. Homogenous and heterogeneous catalysts have been identified as catalysts and among these catalysts. Homogeneous catalysts were chosen because it was possible to generate more biodiesel at a comparatively faster rate. As a feedstock, soybean waste cooking oil (SWCO) was used in this research work. With the help of a conventional mechanical stirrer reactor, SWCO with methanol was heated at various temperatures. As a catalyst, sodium hydroxide (NaOH) and potassium hydroxide (KOH) is used. It evaluated the effect of various parameters such as reaction temperature (60 C, 70 C, and 80 C), the reaction time of 2 hours, and loading of the catalyst (0.5 wt. %, 0.7 wt. %, and 1 wt. % KOH and NaOH). Results show that biodiesel produced from soybean waste cooking oil was within the recommended standards of biodiesel fuel. The transesterification reaction using KOH catalyst was more effective than the NaOH catalyst. The yield and conversion of biodiesel produced from SWCO by using 0.5 wt. % KOH catalysts at 60 C are 93.2 % and 96.16 % respectively while; the yield and conversion of biodiesel produced from SWCO by using 0.5 wt. % NaOH catalysts at 60 C are 91.35 % and 94.5 % respectively. Blends of 10, 20, 30, 50 and 100% by volume of biodiesel derived from soybean waste cooking oil and diesel fuel were prepared as B10, B20, B30, B50 and B100. Biodiesel blends have ASTM standards that are similar to diesel fuel, and the ORSAT apparatus has used to exhaust gas. © Published under licence by IOP Publishing Ltd.