Light weight concrete is an important part in the concrete technology. The use of mineral additives in light-weight concrete, to replace fine aggregate with fly ash and bagasse ash, helps to reduce the cement content. The present investigation aims to meet the performance of light weight concrete, by adding fly ash and bagasse ash, as fine aggregate replacement additives. The strength properties such as cube compressive strength, cylinder compressive strength and split tensile strength were investigated after different ages, to find the optimum addition of mineral additives such as fly ash and bagasse ash, in concrete. The strengths were compared and the optimal replacement level of cement with fly ash and bagasse ash was found. The cylinder compressive strength and split tensile strength of light weight concrete were measured, at the same replacement levels of mineral additives, at the age of 28 days curing. The mathematical equations were proposed to achieve cube compressive and tensile strengths, cylinder compressive and tensile strength and cube compressive and cylinder compressive strengths, concerning typical strength.