The best luggage size for this weight restriction is between 25-29 inches (longest size). That's because 20 or 23 kg checked ...

Carry-on luggage size restrictions vary by airline-here's how to tell if your suitcase, backpack, or duffle bag is small enough to bring as a carry-on.

Size limits won't usually be a concern if you're traveling with standard luggage items like a suitcase; they tend to be relevant with large, awkward items like special sports equipment.