In this study, the behavior of concrete beams with and without fiber was investigated. In the experimental part, a total of 16 beam specimens were manufactured having different section sizes. 12 specimens were reinforced with synthetic fibers, that provide toughness, impact, and fatigue strength to concrete. The fiber ratios of the samples varied between 0% and 0.20% by mass. The samples were subjected to a four-point bending test to obtain the maximum load and displacement values, until they reached the failure modes. Subsequently, the beam samples were modelled in the Abacus finite element analysis software. Due to the comparison of experimental and numerical values and stress distributions of the specimens, it is seen that numerical analysis could be an option when investigating the behavior of beams with different dimensions in four-point bending.