Dirt Truck Load Calculator
How many truck loads your dig actually makes — with swell applied, weight checked against the box, and total haul hours for the fleet you plan to run.
Two limits, and the smaller one wins
A truck stops loading for one of two reasons: the box is full, or the axles are legal-heavy. Light dry material fills the box first. Wet clay, saturated sand or anything with rock in it hits weight long before the box is full — and the loads you actually pay for are set by whichever limit arrives first.
That is why this calculator asks for material weight. A 16 yd³ tri-axle sounds like 16 yards a trip until you put 3,000 lb/yd³ wet clay in it, at which point a 20-ton payload caps you at about 13 yards and your load count jumps by a fifth.
Count loads off loose volume, never bank
Your cut and fill takeoff gives bank volume — soil as it sits in the ground. It bulks up the moment the bucket breaks it. Counting trips off the bank number quietly undercounts the haul by the whole swell factor, which on clay is more than a third. The swell and shrink calculator has typical factors if you do not have your own.
Adding trucks has a ceiling
Total haul time here assumes trucks run independently. In the field they queue at the excavator, and past a certain point another truck just adds another machine waiting in line. Check your loader's output with the excavator production calculator — if the machine cannot fill trucks faster than they return, the fleet is already big enough.
Frequently asked questions
How many cubic yards fit in a dump truck?
Typical struck capacities: single-axle dump 5-8 yd³, tandem 10-14 yd³, tri-axle 14-18 yd³, quad 18-22 yd³, and a semi end dump 20-26 yd³. Those are volume ratings — on heavy wet material you will hit the legal weight limit before you fill the box, which is why this calculator checks both.
Do I use bank or loose volume to count truck loads?
Loose. Soil bulks up 10-40% the moment it comes out of the ground, and it rides in the truck in that bulked state. Counting loads off your bank takeoff undercounts the haul by whatever the swell factor is — on clay that is more than a third of your trips.
Why does my truck hit weight before it is full?
Because dirt is heavy and boxes are sized for volume. Wet clay runs about 3,000 lb per loose cubic yard, so a 16 yd³ tri-axle would be carrying 24 tons — well past a legal payload. On heavy or wet material the payload limit sets your real load size, not the box.
How do I work out total haul time?
Cycle time is load + haul + dump + return + queue. Multiply by the number of loads and divide by how many trucks are running. This calculator does that, so you can see whether adding a second truck actually shortens the day or just leaves both waiting on the excavator.