How it works
The weight of a bulk load is its volume times its bulk density (the weight of a loose pile, including the gaps between pieces).
Volume = length × width × depth
Weight = volume × bulk density
Max even depth = cargo capacity ÷ (density × length × width)
In imperial units, length and width are in feet and depth in inches (divided by 12). One cubic yard is 27 cubic feet. In metric, length and width are in meters and depth in centimeters.
Worked example
A 6 × 10 ft trailer bed filled 6 in deep with gravel, on a trailer with 2,900 lb of cargo capacity.
- Volume: 10 × 6 × 0.5 = 30 ft³ = 1.11 yd³
- Weight: 30 × 105 = 3,150 lb, over the 2,900 lb capacity
- Max even depth: 2,900 ÷ (105 × 60) × 12 = 5.5 in
Bulk material weights
Typical loose densities. Moisture and grading change real values, so check with your supplier.
| Material | lb/ft³ | lb/yd³ | kg/m³ |
|---|---|---|---|
| Gravel | 105 | 2,835 | 1,682 |
| Crushed stone | 100 | 2,700 | 1,602 |
| Sand, dry | 100 | 2,700 | 1,602 |
| Sand, wet | 120 | 3,240 | 1,922 |
| Topsoil, dry | 80 | 2,160 | 1,281 |
| Topsoil, wet | 100 | 2,700 | 1,602 |
| Clay / fill dirt | 110 | 2,970 | 1,762 |
| Compost | 45 | 1,215 | 721 |
| Wood mulch | 25 | 675 | 400 |
| Concrete, wet | 150 | 4,050 | 2,403 |
| Firewood, seasoned (stacked) | 27 | 729 | 432 |
| Firewood, green (stacked) | 39 | 1,053 | 625 |
| Water | 62.4 | 1,685 | 1,000 |
Firewood is shown as stacked wood: a full cord (128 ft³) of seasoned hardwood at 27 lb/ft³ is about 3,456 lb; green, about 4,992 lb.
Know your capacity before the loader shows up
A loader bucket can drop a full yard in one pass, which is enough to overload many trailers. Tell the yard how much you can carry in pounds, not in yards. Find that number with the trailer cargo capacity calculator, and spread the load evenly over and slightly ahead of the axles. Cover loose loads and check your tires with thetrailer tire load calculator.
Common mistakes
- Ordering by volume only. A yard of mulch and a yard of gravel differ by over 2,000 lb.
- Using dry values for wet material. Rain-soaked sand and soil are much heavier.
- Heaping the load. A mounded pile holds more than the flat-depth estimate.
- Forgetting the tow vehicle. The loaded trailer must also fit your tow rating, hitch and payload.