Despite the advantages of using lightweight concrete, its use as a structural elements is relatively small compared to conventional concrete. The density and properties of lightweight aggregates using expanded vermiculite as an alternative to natural river sand in building materials development would improve lightweight concretes. Therefore, the objective of this study is to investigate the strength properties of lightweight concrete M30 with fly ash, metakaolin and vermiculite with natural sand as a partial replacement for cement. In this study, a total of eighteen different concrete mixes were prepared with the replacement of cement with 20% fly ash and fine aggregate with vermiculite proportions from 0 to 25% in 5% increments, and another concrete mix was prepared with the replacement of cement with 10% metakaolin and fine aggregates with vermiculite fractions from 0 to 25% with the addition of 5%. The results were compared with a concrete mix without cement and at various ratios of vermiculite as a replacement for fine aggregate. 54 cubes of dimension 100 mm x 100 mm x 100 mm was cured for 28 days to determine the compressive strength; 54 prisms of dimension 100 mm x 100 mm x 500 mm was cured for 28 days to find flexural strength; and 54 cylinders of 100 mm diameter and height 300 mm was cured for 28 days to determine split tensile strength, all tests were conducted as per applicable Indian standards.