Commercial flights would take approximately 51 hours to fly around the world. The total flight time depends factors that include the weather, the plane's weight, the pilot, and starting or ending locations.
The average commercial jet liner travels about 550 mph, and the Earth is around 26,000 miles in circumference. If a commercial plane could make the trip without refueling, it would take over 47 hours. A large commercial jetliner has a range of about 5,000 miles, so it would need to land and refuel several times.
The record time set for a non-stop flight around the world flight was in a military B-52 in 1980 at 42 hours 23 minutes. It was refueled in flight, which is not an option for commercial aircraft.