Standard size of luggage

The size of luggage on the market is generally based on the airline (International Air Transport Association) carry-on box (hand luggage) and check-in box (check-in luggage) size regulations. For example, Cathay Pacific stipulates that the maximum size of each piece of checked luggage must be less than 158 cm in the sum of the three sides, while the maximum size of each piece of hand luggage must be less than 56x36x23 cm.