The Digital Image Correlation (DIC) method is a low-cost alternative approach to materials research that relies on a camera and software. This method accurately measures deflections, strains, and crack widths in reinforced concrete beams. The accuracy of the DIC method is determined by comparing the results with those obtained from instrumental and theoretical measurement methods. Theoretically, test objects in the form of reinforced beams with varying diameters and different amounts of reinforcement will produce deflection, strain, and crack width values that are dependent on the area of the reinforcement. The analysis of the test results reveals that the Digital Image Correlation (DIC) method provides a level of accuracy that is consistent with the theoretical formula. The accuracy values obtained include deflection results of 0.853, strain values of 0.914, and crack width accuracy values of 0.9705. Moreover, the analysis of the test specimens with the maximum reinforcement area shows that the deflection, strain, and crack width values are lower compared to those with a higher reinforcement area.