Abstract: The influence surface equivalent factor, κ, is essential for converting load survey samples to the equivalent uniformly distributed load. The traditional beam model has limitations when calculating the κ value, including plane simplification and a single influence factor. In this study, the extensive analysis using the refined finite element model is conducted to investigate the κ value by considering multiple factors, such as structural parameters and member positions. The results indicate that the aspect ratio of the column grid is the primary influence factor. The suggested κ values are as follows: 3.0 for the beam end moment and beam midspan shear, which should be considered as a half-span distributed load; 5.0 for the slab midspan moment; and 2.5 for other effects. The equivalent uniformly distributed load is calculated upon the suggested κ values and previous load survey results. The comparison with the previous design load shows that for the slab midspan moment, the load effect is underestimated by about 40% when the previous κ value is used.