By reducing traffic congestion in large cities and providing a safe place to leave vehicles while their owners are doing their activities, parking facilities play an important role in society by reducing congestion and the negative externalities (e.g. CO2 generation, noise, congestion) caused by vehicular traffic, being this one detrimental to society. Additionally, parking lots must establish strategies that allow them to be profitable and remain competitive. We determined the rate of a parking lot with a 20% margin, considering the rate of actual arrivals and the lost arrivals rate when the parking lot is full and the time a vehicle spends in the parking lot. In the results we found the queuing theory is applied to a private parking lot, in addition to establishing an optimal pricing policy, operating policies are established that allow it to generate additional revenue.