BuildMeter guide · Excavation & Drainage
How to Convert Excavation Volume to Truckloads
Turn measured excavation dimensions into bank volume, editable loose-volume allowance and full truckloads without treating one swell factor or truck capacity as universal.
Direct answer
What to know first
Calculate the in-place excavation volume first, then apply a project-specific swell or handling factor to estimate loose hauled volume. Divide that loose volume by the verified usable truck capacity and round upward; soil type, moisture, loading limits and road rules can materially change the result.
Open Excavation Truckload CalculatorStart with in-place excavation volume
Measure the material before excavation as a geometric volume. A rectangular cut uses length × width × average depth. A trench with changing depth should be divided into shorter sections, and irregular pits should be split into simple shapes. Keep all dimensions in one unit before multiplying.
| Shape | Formula | Planning note |
|---|---|---|
| Rectangular cut | Length × width × average depth | Use several depth readings when the bottom or existing ground varies. |
| Trapezoidal section | (Top width + bottom width) ÷ 2 × depth × length | Useful for a straight cut with consistently sloped sides. |
| Circular pit | π × radius² × depth | Use the excavated diameter, not the finished structure diameter. |
| Irregular excavation | Sum of smaller measured sections | Avoid one broad average that hides deep pockets or over-excavation. |
Bank volume and loose hauled volume are not identical
Excavated soil can occupy a different volume after it is loosened, broken, mixed or loaded. Federal Highway Administration earthwork guidance explicitly treats shrink and swell as project factors in cut-and-fill representation. That means one generic conversion should not be presented as authoritative for every soil or rock type.
| Step | Calculation | Input to verify |
|---|---|---|
| 1. Bank volume | Measured in-place geometry | Survey, field dimensions and excavation limits |
| 2. Loose volume | Bank volume × (1 + entered swell allowance) | Material-specific project estimate or measured production data |
| 3. Truckloads | Loose volume ÷ usable truck capacity | Actual body capacity and legal payload |
| 4. Purchase or disposal plan | Round loads upward and review weight | Hauler, disposal site and roadway constraints |
Worked example
A rectangular excavation is 30 ft long, 12 ft wide and averages 3 ft deep. The bank volume is 30 × 12 × 3 = 1,080 ft³, or 40 yd³. With an editable 20% loose-volume allowance, the planning volume becomes 48 yd³. At a verified usable capacity of 12 yd³ per truck, the estimate is 48 ÷ 12 = 4 truckloads.
If the same hauler can legally carry only 10 yd³ of that material because of weight, the quantity becomes 4.8 and must round upward to 5 truckloads. Capacity should therefore be checked by both volume and payload.
Volume conversions
- 1 cubic yard = 27 cubic feet.
- 1 cubic yard = exactly 0.764554858 cubic metre.
- 1 cubic metre is approximately 1.30795 cubic yards.
NIST publishes the underlying volume conversion factors. Preserve extra precision during the calculation and round only the final planning result.
Common mistakes
- Using finished structure dimensions instead of the actual excavation limits.
- Applying one assumed swell factor to clay, sand, mixed fill and broken rock.
- Dividing by nominal truck body volume without checking payload limits.
- Rounding truckloads down.
- Ignoring access, loading efficiency, partial final loads and disposal-site restrictions.
- Counting material that will be reused on site as exported spoil.
Use the calculators
Use the Excavation Truckload Calculator when hauling is the main question. Use the Excavation Calculator for general volume and cost planning, the Trench Spoil Volume Calculator for linear trenches, and the Soil Compaction Calculator when comparing loose and placed fill.
Sources and professional limits
This guide explains a planning workflow, not a geotechnical determination or transport authorization. Excavation support, underground utilities, contaminated soil, safe slopes, shoring, traffic routes and legal axle or payload limits require project-specific review.