It is known that photovoltaic generation may cause voltage variations and imbalances, harmonics of current and voltage, flickers, reverse power flow, additional aging in medium/low distribution transformers, and voltage regulators. A way to reduce these consequences is to select an adequate level of PV generation in the distribution systems. PV Hosting Capacity (PVHC) is intended to achieve this goal by the determination of the maximum PV generation allowed in the system. This work presents a practical method to calculate the PVHC in a medium voltage feeder, analyzing the relationship between the load factor of the distribution transformer and the voltage, the current, and the active power when the PV solar penetration level changes. The results allowed to conclude that there is a direct relationship between PV solar penetration level and a load factor of the distribution transformers.