If they are 4' x 4' then you can fit 2 rows of 12, or 24 pallets.
If you can stack the freight 2 high, you can get 48 pallets in there.
28
22
26 standard size pallets
Yes, If load the pallets sideways and double stack them you can fit 60 pallets on a 53' trailer
20
24
22 is the minimum count.
26-30 single
Standard pallets are 4 feet so single file would be 12. If you put them side by side which is common 24.
26 skids (standard 40x48) side by side total. if you are willing to load pallet side way you can load up to 30 pallets. Assuming all pallets are not stackable.
Assuming you mean a 48 ft. trailer with at least 96 inches of deck width, and you're using standard 40"x48" pallets, you could fit two across and 14 long for a total of 28 single stacked pallets.
how many chep pallets will fit in a 20' container