A typical dumpster can hold 1616 gallons of waste. That is about 8 cubic yards of waste in a dumpster.
A large black garbage bag is about ¼ of a cubic yard; thus, four black bags equal 1 cubic yard.
A dumpster holds about 32 full black garbage bags.
By compacting that waste, the volume is reduced enough to be emptied 4 times less often.
A rule of thumb for a non-compacted and compacted waste ratio is between 25-1 and 20-1.
This means about ¾ of the dumpster waste could be compacted to a single black garbage bag.