Swell Factor
The percentage a material expands when excavated from its natural bank state. Sand swells 10–15%, common earth 20–30%, clay up to 40%, blasted rock 50%. Haul trucks carry loose volume, so trip counts are computed on swelled — not bank — yardage.
Where this appears in real estimates
This term isn't trivia — it's a working variable. These tools use it directly:
- swell factor estimate tool — Compute swell percentage from bank and loose volumes, or convert between them.…
- figure your excavation numbers — Dig volume in bank and loose cubic yards, with swell and truckload counts.…
- trench calculator — Trench spoil volume for utilities, footings and drains by length, width, depth.…
Go deeper
- Crusher Run vs Clean Gravel — head-to-head decision guide
- Privacy Fence Installation — full project walkthrough
- Asphalt Cost in Florida — local pricing & climate
- Read the field guide on the blog — practitioner-level detail
- Related engineering article — from our licensed engineer
Reviewed: · Part of the CalculatorAsphalt Construction Glossary · Sources: see methodology & standards.