How to calculate excavation
Loose cubic yards = Bank cubic yards × (1 + swell %)
Soil in the ground ("bank" volume) is compacted. Once dug, it breaks up and takes more space — this is called swell. That loose volume is what you need to haul.
Example: a 20 ft × 30 ft area dug 2 ft deep is 1,200 cubic feet = 44.4 bank cubic yards. With 25% swell that becomes about 55.6 loose cubic yards — around 6 dump-truck loads.
Typical swell factors
| Soil | Typical swell |
|---|---|
| Sand and gravel | 10–15% |
| Common earth / loam | 20–30% |
| Clay | 30–40% |
| Rock (blasted) | 50% or more |
Before any digging in the US, call 811 (free) to have underground utility lines marked.
Frequently asked questions
What is the swell factor?
How much soil expands once it is dug up. 25% swell means 1 cubic yard in the ground becomes about 1.25 cubic yards in the truck.
How many cubic yards fit in a dump truck?
About 10–14 cubic yards for a standard tandem dump truck; small trucks carry 5–6.
How much does a yard of dirt weigh?
Loose dirt weighs roughly 2,000–2,700 lb per cubic yard depending on soil type and moisture.
Do I need to call before I dig?
Yes — in the US, call 811 a few days before digging to have buried utilities marked for free.
Related calculators
These figures are estimates for planning only. Material weights and coverage vary by supplier, moisture and compaction. Always confirm quantities and prices with your supplier before ordering. See our terms & disclaimer.