Soil Excavation Calculator
Excavated volume, bulking, skip loads and grab lorry loads
Inputs
Note: Skip and lorry loads are approximate. Always check local skip sizes and weight limits.
Results
Enter excavation dimensions then click Calculate.
TXTexas IBC / IRC (AHJ amendments)
References & Sources
Standards Cited
- OSHA 29 CFR 1926 Subpart P — Excavations
Provides guidance on excavation safety, soil classification, and foundation design relevant to volume calculations
Formulas Used
- Excavated Volume:
V = length x width x depth
Source: Standard geometry - Loose Volume (with bulking):
looseVolume = excavatedVolume x bulkingFactor
Source: Construction industry practice — Soil expands when disturbed; bulking factor accounts for this - Volume in Cubic Yards:
yd³ = m³ x 1.308
Source: NIST conversion factor - Weight Estimate:
tonnes = (excavatedVolume x in-situ density) / 1000
Source: Construction industry practice - Skip Loads:
skips = ceil(looseVolume_yd³ / 8)
Source: Industry standard (8-yard skip capacity) - Grab Lorry Loads:
loads = ceil(looseVolume_m³ / 12)
Source: Industry standard (16-tonne grab lorry holds approx. 12 m³ loose soil)
Key Assumptions
- Clay soil bulking factor: 1.35 (35% expansion) — Standard construction industry bulking factors
- Sand bulking factor: 1.15 (15% expansion) — Standard construction industry bulking factors
- Loam/topsoil bulking factor: 1.25 (25% expansion) — Standard construction industry bulking factors
- Gravel bulking factor: 1.12 (12% expansion) — Standard construction industry bulking factors
- Rock bulking factor: 1.50 (50% expansion) — Standard construction industry bulking factors
- In-situ densities: clay ~1800 kg/m³, sand ~1600 kg/m³, loam ~1400 kg/m³, gravel ~1700 kg/m³, rock ~2200 kg/m³. Weight uses in-situ volume × in-situ density (mass is conserved regardless of bulking) — Construction industry standard values