FAA says number of drones in the US will reach 7 million by 2020

An estimated seven million drones will fly in US skies by 2020, nearly tripling the number expected to be in circulation by the end of the year, the Federal Aviation Administration said.

"Unmanned aircraft systems will be the most dynamic growth sector within aviation," the agency said in a report, which forecast that some 2.5 drones million will be in use by the end of 2016.

How the civilian drone market evolves, however, will depend on future security and regulatory measures put in place by the US government, the FAA said, emphasizing that "unprecedented milestones" were already set in 2015.

In December of last year, the FAA released rules requiring registration of small unmanned aircraft weighing more than 250 grams (0.55 pounds) and less than 25 kilograms (55 pounds), including payloads such as on-board cameras.

"This registration rule will aid in investigations and allow the FAA to gather data," the agency said in its report.

The number of hobby drones is expected to climb from 1.9 million in 2016 to 4.3 million in 2020, while commercial drones are predicted to soar from 600,000 to 2.7 million.

However, the FAA added that predictions for commercial drones "are more difficult to develop given the dynamic, quickly-evolving nature of the market."

The FAA will publish final regulations regarding drone use within the next few months, it said.

The agency worked with Teal Group, a drone industry expert, to better understand the market for unmanned aircraft systems.

An estimated 90 percent of the drone fleet in 2020 will cost an average of $2,500. The most expensive models may reach $40,000.