In the United States, there are about 5,000 commercial airplanes in the sky at any one time, as reported by Daily Mail. The website Flightrader 24 enables people to track the total number of airplanes at any given moment.
Flightradar 24 gets its data from the Federal Aviation Administration in the United States and the automatic dependent surveillance broadcast (ADS-B) system. The ADS-B system is used in other countries, and it's interesting to note that only 60 percent of airplanes are equipped with ADS-systems. Therefore, the actual number of planes flying at any moment may be more than 5,000.