Unconfined compression strength is one of the most important engineering parameters in rock mechanics; it is used to characterize and study the behavior of solid rocks. A good correlation between the unconfined compression strength test (UCS) and the point load strength (PLS) can be very useful because it allows for faster and cheaper testing than others with the same security to calculate the structures and performances of solid rocks. A preliminary step to implement the correlation is to have a good method to determine resistance to point load. This determination is quite correct if you have a sufficient number of tests on specimens of the same nature, but usually it does not occur and it is necessary to apply a size correction factor, F = (De / 50) α , with α = 0.45. This paper is based on limestone from Comunidad Valenciana (Spain) because it represents a very high percentage of their rocks. The implementation has been conducted over 700 field and laboratory tests of which 255 are PLT test, 45 are UCS test, and the rest are other parameters like: porosity and specific weight, Slake Durability, and ultrasonic velocity, among others.