You can speak the carpet’s command word as an action to make the carpet hover and fly. It moves according to your spoken directions, provided that you are within 30 feet of it.
Four sizes of carpet of flying exist. The GM chooses the size of a given carpet or determines it randomly.
d100
Size
Capacity
Flying Speed
01–20
3 ft. × 5 ft.
200 lb.
80 feet
21–55
4 ft. × 6 ft.
400 lb.
60 feet
56–80
5 ft. × 7 ft.
600 lb.
40 feet
81–100
6 ft. × 9 ft.
800 lb.
30 feet
A carpet can carry up to twice the weight shown on the table, but it flies at half speed if it carries more than its normal capacity.
RollQuest ships the D&D 2014 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.