Compaction control in the field can be assessed via sand-cone and nuclear gauge tests. In this study, the data obtained from a series of sand cone and nuclear gauge tests are used to establish relationships between several outcomes of these tests. Comprehensive statistical analyses are applied to the data at hand. Next, linear/nonlinear regression analyses and artificial neural networks are used to express the correlation between the results of two tests. As a consequence, the combined usage of the tests in civil engineering practice is evaluated.