Quick answer
For simple rectangular earthwork, multiply length by width by average depth. For sloped or irregular excavation, split the area into sections or use average end areas. Keep cut, fill, swell and compaction assumptions separate.
Step by step
- Map the work Separate excavation, imported fill and stockpile areas.
- Measure average depth Record high and low points when depth changes.
- Calculate in-place volume Use the designed geometry before applying material behavior.
- Review swell and compaction Loose haul volume and compacted fill volume are not the same.
Formula or rule of thumb
Example
A 30 ft × 20 ft excavation with an average depth of 2 ft contains 1,200 ft³, or 44.44 yd³ in place.
Common mistakes
Using one maximum depth for the whole site, treating trucked loose soil as compacted fill, and ignoring unsuitable material or disposal.
Planning note: product yields, installation methods, site conditions and local requirements can change the final quantity. Use the exact manufacturer or supplier information before purchasing.
FAQ
What is swell?
Excavated soil may occupy more loose volume than it did in place.
What is shrinkage?
Placed fill may require more loose material to achieve a compacted volume.
Is this a grading plan?
No. Complex sites need survey and earthwork design.