In order to evaluate the strength of concrete in an existing structure, the semi-destructive method in situ is always challenging. In some cases, it is necessary to apply core testing on members such as columns, where performing a core testing in a column causes a cylindrical or cubic hole in it, which has a negative effect on the bearing capacity of the member. In other words, the geometry of the core test as well as the ratio of the volume and width/diameter of the hole to the site in the concrete affect the member, and on this basis, the aforementioned ratios have a significant effect on measuring the site strength. In this study, the effect of the hole on the compressive strength of 8 series of 5 concrete samples with dimensions of 15x15x15 of different sizes and cylindrical and cubic geometries was prepared. The linear relationship between the uniaxial compressive strength of concrete and the ratio of the hole diameter to the width of the sample and the relationship between the uniaxial compressive strength of concrete and the ratio of the hole volume to the sample volume were obtained based on the experimental and numerical model in the form of a load perpendicular to the hole. The results show that if the volume and diameter of the hole are about 14 and 60 percent of the volume and width of the sample, respectively, it can reduce the uniaxial compressive strength by 58 and 74 percent.