Glass fiber reinforced polyester composites have played a dominant role for a long-time in a variety of applications for their high specific strength, stiffness and modulus. In this research work, an E-glass fiber with random oriented reinforced polymer composite was developed by hand lay-up technique with varying fiber percentages (15%, 30%, 45%, and 60% by weight percentage). The influence of glass fiber percentage on the mechanical properties such as tensile strength, bending strength and impact strength was investigated. Hardness of composites was evaluated by using Brinell hardness tester. The results showed remarkable improvement in the mechanical properties of the fabricated composite with an increasing in the glass fiber contents. Tensile strength varies from 28.25 MPa to 78.83 MPa, flexural strength varies from 44.65 MPa to 119.23 MPa and impact energy at room temperature varies from 3.50 Joules to 6.50 Joules, as a function of fiber weight fraction. The hardness value will greatly increase from 31.5 BHN to 47 BHN. The best mechanical properties obtained at 60 wt.% of glass fiber of fabricated composites.