Excavation quantities: from bank volume to truck planning
An excavation estimate is more than the geometric volume of a hole. Soil normally occupies more volume after excavation, while truck body volume, actual payload, moisture and legal weight limits can control hauling. This guide follows the practical chain bank excavation → swell → loose volume → approximate mass → truck loads.
Content and method reviewed: 19 September 2026
Bank, loose and compacted volume are not the same
Bank volume is the soil volume before excavation. Disturbance increases voids, so loose volume is commonly larger. Compacted fill is a third condition and should not be calculated by simply reversing a swell percentage.
Loose volume = bank volume × (1 + swell / 100)
Example: 500 m³ (654 yd³) of bank excavation at 25% swell becomes about 625 m³ (817 yd³) loose.
Typical swell ranges for preliminary estimating
Use these only for early quantity checks and scenario comparisons. Project geotechnical data, measured field factors and contract requirements take precedence.
| Material | Preliminary swell range | Estimating note |
|---|
| Sand / gravel | about 10–20% | Gradation and moisture can change behavior. |
| Common soil / topsoil | about 20–30% | A mid-range value can be used for scenario checks. |
| Clay / silt | about 25–40% | Moisture and excavation method can be important. |
| Broken rock | about 40–60%+ | Fragment size and excavation method strongly affect volume. |
These are not specification values. The calculator allows the swell percentage to be overridden.
Worked example: foundation excavation to hauling plan
Consider a 65.6 ft × 49.2 ft × 9.84 ft excavation (approximately 20 m × 15 m × 3 m). Bank volume is about 1,177 yd³ (900 m³). With 25% swell, loose volume becomes about 1,471 yd³ (1,125 m³).
| Bank excavation | ≈1,177 yd³ / 900 m³ |
|---|
| Swell | 25% |
|---|
| Loose volume | ≈1,471 yd³ / 1,125 m³ |
|---|
| Effective truck volume | ≈19.6 yd³ / 15 m³ per load |
|---|
| Theoretical loads | 75 loads |
|---|
A truck body may physically hold that volume but reach its payload limit first. Always check both volume and allowable weight.
How truck capacity changes the load count
For 1,125 m³ (about 1,471 yd³) of loose excavation:
| Effective capacity | Theoretical loads | Planning note |
|---|
| 13.1 yd³ / 10 m³ | 113 | Round partial loads upward. |
| 15.7 yd³ / 12 m³ | 94 | Volume basis only. |
| 19.6 yd³ / 15 m³ | 75 | Worked-example case. |
| 23.5 yd³ / 18 m³ | 63 | Check payload. |
| 26.2 yd³ / 20 m³ | 57 | Check legal weight limits. |
Converting excavation volume to approximate weight
Hauling is sometimes controlled by tons rather than cubic yards. Approximate mass is the loose volume multiplied by an appropriate loose bulk density.
Approximate mass = loose volume × loose bulk density
Do not assume one density for every soil. Moisture, gradation and degree of loosening can materially change payload.
Sloped excavations need a different geometry
If the excavation is wider at the top than at the base, length × base width × depth can understate the quantity. Include the side-slope geometry in the cross-section; for changing sections, use station-based average-end-area or another appropriate volume method.
6 checks before using an excavation haul estimate
1. GeometryVerify dimensions against drawings and survey elevations.
2. SwellUse a project-appropriate field or geotechnical factor.
3. DensityIf tons are needed, verify loose bulk density.
4. PayloadCheck legal and technical weight limits as well as body volume.
5. Fill factorLoading method and body geometry can reduce effective volume.
6. BalanceSeparate reusable on-site material from exported spoil.
Frequently asked questions
Why does 1 cubic yard of bank excavation become more than 1 cubic yard to haul?
Excavation disturbs the soil structure and usually increases void space. Apply an appropriate swell factor to estimate loose hauling volume.
How many truck loads are needed for an excavation?
Calculate loose volume after swell, divide by effective truck capacity and round partial loads upward. Then verify that payload weight does not govern first.
How do I convert excavation cubic yards to tons?
Multiply loose volume by a representative loose bulk density in compatible units. There is no single density that is correct for every soil.
Are swell and compaction the same?
No. Swell describes volume increase after excavation; compaction describes densification when material is placed as fill.
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