When to use this calculator
Estimate loose spoil volume after a chosen expansion allowance. Swell is material-specific and is not the same as a compaction loss.
Explore the material quantities calculators for other questions in this topic. For a related calculation, use the Stair Stringer Length Calculator: Estimate the sloping length of a straight stair stringer.
PUTTING IT INTO PRACTICE
Soil Swell Volume: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| In-situ excavation volume (m³) | 30 |
| Swell allowance (%) | 20 |
| Result | 36 m³ |
- Check the input labels and enter the example values above.
- Apply the relationship: Loose volume = in-situ volume × (1+swell/100).
- The result is 36 m³, rounded for display.
How to interpret your result
Swell is material-specific and is not the same as a compaction loss.
Calculate net geometric quantities first, then apply a project-specific allowance where appropriate. Coverage per bag or pack should come from the product label. Bulk density, trimming and compaction can substantially change order quantities.
Frequently asked questions
Does a geometric estimate include waste automatically?
Only when a waste or allowance input is provided. Otherwise add an appropriate allowance separately before ordering.
When is the soil swell volume calculator useful?
Estimate loose spoil volume after a chosen expansion allowance. Swell is material-specific and is not the same as a compaction loss.
How do I use the soil swell volume calculator?
Enter in-situ excavation volume (m³), swell allowance (%). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Loose volume = in-situ volume × (1+swell/100).
What should I check before using the result?
Swell is material-specific and is not the same as a compaction loss.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
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