How much weight will a single axle dump truck hold?

It depends on the vehicle class of the truck and if they are subject to the federal DOT regs. Most states mirror the same but some might have different weights for intrastate operations. All dump trucks are not the same and this info is for the US.

A class 3 which would be a 1 ton truck with a dump bed will have a 14,000 lbs max weight limit. Subtract the weight of the truck from that and you will get the weight it can hold. A class the class 7 heavy truck weight limit is between 26,001- 33,000 lbs which is about the most you will see without tandem axles. Again, subtract the curb weight from the max weight and check the manufacturer's gross vehicle weight rating (GVWR) to ensure it isn't listed below the max class rating.

A typical max weight of the load for a class 3 might be 4,000 - 6,000lbs (2-3 tons) the max weight of the load for a class 7 dump truck might be around 12,000 lbs or 6 tons up to about 18,000lbs or 9 tons. Of course lighter trucks will carry more and heavier trucks have to carry less.