Single-axle dump
about 10 cubic yards
Dump truck & semi load sizes
These are typical box volume defaults for planning. Actual legal payload varies a lot with tractor and trailer empty weight, axle configuration, route/bridge limits, and whether the carrier is running an overweight permit.
Dump trucks
Tandem dump
about 14 cubic yards
Tri-axle dump
about 16 cubic yards
Quad-axle dump
about 18 cubic yards
Semi trailers
Each trailer dumps differently — end off the rear, side off the flank, belly through the floor.
Semi — end dump
about 26 cubic yards
Bed lifts and material dumps off the rear — usually a bit more usable box volume than a side dump.
Semi — side dump
about 24 cubic yards
Tub is hinged on the dump side; the far side lifts and material rolls out over the hinge. Frames/hydraulics can eat a little internal space.
Semi — belly dump
about 24 cubic yards
Planning capacity is typically near side dumps. Unloads through bottom hopper gates into a windrow.
Weight vs volume
Dense materials (road base, wet rock, RAP) are often weight-limited long before the box is full. A lighter truck/trailer combo can haul more payload tons than a heavy one under the same legal gross. Carriers with overweight permits may legally haul more than standard limits — but that is carrier- and route-specific. Ask your hauler what they actually put on that truck.