Results
Compacted Volume
0yd³
Loose Volume
0yd³
Volume Difference
0yd³
Swell Factor Used
0%
Compacted Weight
0tons
Truck Loads (14 yd³)
0loads
📦 Compacted to Loose Volume Calculator (Swell Factor)
Convert between compacted (bank) volume and loose (hauled) volume for earthwork, excavation, and paving projects. Select your material type to automatically apply the correct swell factor.
Swell Factor Reference Table
The swell factor (or bulking factor) represents how much a material's volume increases when it's excavated from its compacted, in-place state. Use these values for earthwork calculations:
| Material | Swell Factor | Compacted Density (lbs/ft³) | 1 yd³ Compacted → Loose |
|---|---|---|---|
| Sand | 10–15% | 100–120 | 1.10–1.15 yd³ |
| Gravel | 10–15% | 105–120 | 1.10–1.15 yd³ |
| Crushed Stone | 10–15% | 100–110 | 1.10–1.15 yd³ |
| Topsoil | 20–30% | 75–100 | 1.20–1.30 yd³ |
| Clay (Dry) | 20–30% | 100–120 | 1.20–1.30 yd³ |
| Clay (Wet) | 30–40% | 110–130 | 1.30–1.40 yd³ |
| Loam | 20–30% | 80–100 | 1.20–1.30 yd³ |
| Blasted Rock | 40–65% | 150–170 | 1.40–1.65 yd³ |
| Ripped Rock | 30–45% | 140–160 | 1.30–1.45 yd³ |
| Milled Asphalt (RAP) | 10–20% | 110–145 | 1.10–1.20 yd³ |
| Demolished Concrete | 40–60% | 130–150 | 1.40–1.60 yd³ |
Understanding Compacted vs Loose Volume
In earthwork and construction, material exists in three volume states:
- Bank (In-Place) Volume: The undisturbed, naturally compacted volume of material in the ground. This is what you measure on plans and surveys.
- Loose (Hauled) Volume: The volume of material after it's been excavated, loaded, or stockpiled. It's always larger than bank volume due to air voids created during excavation.
- Compacted Volume: The volume after material has been placed and mechanically compacted (roller, plate compactor). This can be equal to or less than bank volume.
Why This Matters for Your Project
- Ordering Materials: Suppliers sell materials in loose volume. If your plans show 100 yd³ compacted, you need to order 110–165 yd³ loose depending on material type.
- Truck Load Planning: A standard dump truck carries 10–14 yd³ of loose material. You need to know the loose volume to calculate the number of truck loads.
- Excavation Quantities: When excavating, the material swells. 100 yd³ of in-place soil becomes 120–140 yd³ of spoil that needs hauling away.
- Cost Estimation: Material costs are based on loose volume. Getting the conversion wrong can result in 15–65% cost overruns.
How to Calculate Compacted to Loose Volume
Formula: Compacted → Loose
Loose Volume = Compacted Volume × (1 + Swell Factor ÷ 100)
Example: You need 200 cubic yards of compacted gravel (12% swell):
Loose Volume = 200 × (1 + 12/100) = 200 × 1.12 = 224 cubic yards
You need to order 224 yd³ of loose gravel to get 200 yd³ after compaction.
Formula: Loose → Compacted
Compacted Volume = Loose Volume ÷ (1 + Swell Factor ÷ 100)
Example: You have 500 cubic yards of loose clay (35% swell). After compaction:
Compacted Volume = 500 ÷ (1 + 35/100) = 500 ÷ 1.35 = 370 cubic yards
Practical Applications
Road Construction
When building a road base, the engineer specifies compacted thickness (e.g., 8 inches compacted aggregate). The contractor must order enough loose material to achieve this compacted depth. For crushed stone with 12% swell, an 8-inch compacted layer requires about 9 inches of loose material before compaction.
Foundation Excavation & Backfill
When excavating for a foundation, the removed soil swells 20–40%. A 100 yd³ excavation produces 120–140 yd³ of spoil. If hauling away, plan truck loads based on loose volume. If backfilling, the soil will compact back to approximately its original bank volume.
Landscaping & Grading
When ordering topsoil or fill dirt, remember that delivered material is loose. If you need 50 yd³ of compacted fill, you need to order approximately 60–65 yd³ of loose material (25% swell factor for topsoil).
Frequently Asked Questions
What is the difference between compacted and loose volume?
Compacted volume (also called bank volume or in-place volume) is the volume of material after it has been compacted to its final density. Loose volume is the volume of the same material when it's been excavated, dumped, or stockpiled — it takes up more space because of air voids between particles. The ratio between them is called the swell factor. For example, 1 cubic yard of compacted clay becomes approximately 1.30–1.40 cubic yards when loose.
How do you convert compacted volume to loose volume?
To convert compacted volume to loose volume, multiply the compacted volume by (1 + swell percentage ÷ 100). For example: 100 cubic yards of compacted gravel with a 12% swell factor = 100 × 1.12 = 112 cubic yards loose. This means you need to order 112 yd³ of loose gravel to get 100 yd³ after compaction.
What is a swell factor in earthwork?
A swell factor (also called bulking factor) is the percentage increase in volume when material is excavated from its compacted state. Common swell factors: sand 10–15%, gravel 10–15%, clay 20–40%, topsoil 20–30%, crushed stone 10–15%, and blasted rock 40–65%. Knowing the swell factor is essential for ordering materials, planning haul truck loads, and budgeting earthwork projects accurately.
How do you convert loose volume to compacted volume?
To convert loose volume to compacted volume, divide the loose volume by (1 + swell percentage ÷ 100). For example: 115 cubic yards of loose gravel with a 12% swell factor = 115 ÷ 1.12 = approximately 103 cubic yards compacted. This tells you how much final compacted volume you'll get from a given amount of loose material.
Why is compacted to loose volume conversion important?
This conversion is critical for: ordering the right amount of material (plans show compacted volume but you buy loose volume), estimating haul truck loads (trucks carry loose material), calculating excavation spoil quantities (material swells when dug up), and budgeting accurately. Getting this wrong can result in 15–65% material shortages or overorders.