Dump truck capacity in cubic yards
There is no single number. A truck has a volume limit and a weight limit, and the material you load decides which one it hits first.
Last updated 3 September 2026
The two limits
- Volume. The body has a struck capacity — level with the top of the sides — and a heaped capacity that assumes the load stands in a crown. Both are on the body plate or the body maker’s sheet. Use struck for anything that flows; a heap of dry sand does not stay a heap.
- Weight. The door label states the gross vehicle weight rating (GVWR). Payload is that rating minus the truck’s empty weight, which a scale ticket gives you exactly. On public roads the axle and gross limits below apply as well, whatever the label says.
Federal weight limits on the Interstate
The limits in 23 CFR § 658.17 apply on the Interstate system and set the ceiling most heavy trucks are built to. States set their own on other roads and issue overweight permits, so the label and the state rule both matter — but no permit changes what the body holds.
| Limit | Pounds |
|---|---|
| Maximum gross vehicle weight | 80,000 |
| Any single axle | 20,000 |
| Tandem axles | 34,000 |
Bridge Formula — the limit for any group of consecutive axles
W = 500 × (L × N ÷ (N − 1) + 12 × N + 36)
W is the allowed weight in pounds on the group, L the distance in feet between the first and last axle of the group, N the number of axles in it. It is why a longer truck may carry more, and it is the rule that often binds before 80,000 does.
Which limit binds
Payload
Payload = GVWR − Empty weight
Both from the truck: the label and a scale ticket. Not from a brochure — options, a tarp system and a full fuel tank all add to the empty weight.
Weight-limited volume
Weight-limited volume = Payload ÷ Material density
Density of the loose material, in pounds per cubic yard, from the supplier’s ticket or a measured load. This is the figure that changes with the material — and with its moisture.
Volume per load
Per load = the smaller of Body capacity and Weight-limited volume
If the weight-limited volume is smaller, the truck is weight-bound and leaves with the body not full. If it is larger, the truck is volume-bound and the body is the limit.
Loads
Loads = Total loose volume ÷ Per load, rounded up
Loose volume — the material has already swelled by the time it is in the truck. See the bank vs loose guide for the conversion.
A worked example
Suppose a truck’s body plate says 14 cubic yards struck, its door label says a GVWR of 58,000 lb and a scale ticket says it weighs 26,000 lb empty. Those three numbers are the inputs to this example — they describe one hypothetical truck, not a class of truck. Its payload is 58,000 − 26,000 = 32,000 lb. The job is 120 loose cubic yards, and the supplier tickets give two different densities for two materials.
| Material (density from ticket) | Weight-limited volume | Per load | Binds | Loads for 120 cu yd |
|---|---|---|---|---|
| Heavy material (2,700 lb/cu yd) | 32,000 ÷ 2,700 = 11.9 cu yd | 11.9 cu yd | Weight | 11 |
| Light material (1,800 lb/cu yd) | 32,000 ÷ 1,800 = 17.8 cu yd | 14.0 cu yd | Volume | 9 |
Same truck, same job, 2 extra loads — because the heavy material fills the weight rating at 11.9 yards while the body could take 14. Bid the heavy material on the body volume and the shortfall is 22% of the trips.
Why there is no capacity table here
- Body volume varies by body, not by truck class. Two trucks on the same chassis can carry bodies that differ by several yards.
- Payload varies with the chassis, the axle configuration, the options fitted and the fuel on board. It is on the label and the scale, and nowhere else.
- The binding limit depends on the material, so a volume figure alone is not a capacity. A table of body volumes would be read as a table of loads, and it is not one.
- State weight rules differ from the federal ones on non-Interstate roads. The number that applies is the one for the road the truck is on.
How Calcumetryx handles it
The dirt hauling calculator asks for the body volume, the payload and the material density, works out both limits and tells you which one binds — then gives the load count on the binding one. Leave the density blank and it reports the volume-bound count and says the weight check is missing, rather than assuming a density for you.
Sources
- 23 CFR § 658.17 — Weight — Code of Federal Regulations, via Legal Information Institute, Cornell Law SchoolSupports: The 80,000 lb gross, 20,000 lb single-axle and 34,000 lb tandem limits and the Bridge Formula. · checked 3 September 2026
- Payload, weight-limited volume and load count are defined by the formulas above — Arithmetic — verifiable by handSupports: The worked example. Its truck and material figures are stated inputs, not typical values. · checked 3 September 2026
Put it to work
All construction calculators →Work out the loose volume first, then the loads — with your truck’s figures and your material’s density.