Dynamic formulas in practice of deep foundation engineering has been target of extensive discussions, criticisms and controversies since the late 19th century. The fundamental reasons for it stands both in the theoretical basis of most formulas, that do not represent the pile driving phenomenon so well, and the fact formulas functionalities were frequently misunderstood and misapplied by some engineers. As both causes are linked, it is a fact that the awareness of a dynamic formula limitation and inaccuracy, with the knowledge of its very main purposes, can make its applicability much more cautious and conscious, turning it to an useful tool for pile driving‘s quality control, as it remains one of the most simple and inexpensive obtainable information. In this respect, the present paper contributes with a Simplified Hiley Formula calibration for a site in the city of Duque de Caxias, Brazil, where 32 precast concrete piles were dynamically tested. The formula estimations were made with records of set and elastic rebound, collected during perform of the tests. The calibrated formula was applicated later to a neighbor site construction where other 44 concrete piles were also tested for confirming the dynamic formula estimations. The calibration provided improved results, with more accurate estimations of the ultimate piles capacities for the local subsoil. It‘s also presented an alternative for estimating the effective transferred energy to the piles, what could spare the necessity of pile driver‘s efficiency estimation when in difficult conditions.