Fill Dirt Calculator
Calculate how much fill dirt you need in cubic yards, cubic meters, and tons for your excavation or grading project.
Enter dimensions and click Calculate.
How Does the Formula Work?
The fill dirt calculator determines how much material you need to fill, grade, or backfill an area. It computes volume from your area dimensions and depth, converts between metric and imperial units, estimates weight based on soil type, and calculates the number of dump truck loads required for delivery.
Rectangular: Length × Width × Depth
Circular: π × (Diameter/2)² × Depth
Triangular: 0.5 × Base × Height × Depth
Weight = Volume × Soil Density
Soil Densities (compacted):
Fill Dirt: 1,600 kg/m³ | Topsoil: 1,350 kg/m³
Sand: 1,550 kg/m³ | Gravel: 1,800 kg/m³ | Clay: 1,750 kg/m³
Example: 10m × 5m × 30cm fill dirt
Volume = 10 × 5 × 0.3 = 15 m³ (19.6 yd³)
Weight = 15 × 1,600 = 24,000 kg = 24 tons
Truck loads = 2 (at 10 m³ each)
Choosing the Right Soil Type
Fill dirt is subsoil — the layer below topsoil that has been stripped of organic matter. It is used for grading, building up low areas, filling foundations, and creating stable bases because it compacts well and does not decompose. Topsoil contains nutrients and organic matter, making it suitable for gardens and lawns but less stable for structural fill. Sand drains well and is used under pavers and around drainage systems. Gravel provides excellent drainage and load-bearing capacity for driveways and road bases. Clay compacts tightly but drains poorly, used where impermeability is needed.
Accounting for Compaction
When fill dirt is delivered loose and then compacted, it loses 10–30% of its volume depending on soil type and compaction method. Sandy soils compact less (10–15%), while clay-rich soils can compact up to 30%. A common rule of thumb is to order 15–20% more material than the calculated volume. For engineered fill projects that require specific compaction levels (like 95% Modified Proctor density), consult with a geotechnical engineer for precise specifications.
Truck Load Estimates
Standard dump trucks carry 10–12 cubic meters (13–16 cubic yards) of material, while smaller trucks carry 5–6 cubic meters (6–8 cubic yards). The calculator provides estimates for both sizes. Actual capacity depends on the truck model and weight limits — a truck may hold 12 cubic yards by volume but be limited to 10 cubic yards of gravel because of weight restrictions. Always confirm capacity and pricing with your local supplier before ordering.
Common Fill Dirt Projects
Typical residential projects include raising a low yard, filling in a pool, creating a level building pad, backfilling a retaining wall, or grading around a foundation for proper drainage. For these projects, specify the area shape, measure the longest and widest dimensions, and determine the average fill depth needed. If the terrain is uneven, measure depth at multiple points and use the average. Commercial projects like road construction and site grading involve much larger volumes and should work with a civil engineer for precise quantities.
Tips & Recommendations
Fill dirt compresses when compacted. Order 15–20% more than calculated to account for settling and compaction loss.
Rectangular for most areas, circular for round projects, triangular for wedge-shaped fills. Labels update automatically.
Fill dirt, topsoil, sand, gravel, and clay — each with accurate density for weight estimation. Choose what matches your project.
See how many standard (10 m³) or small (6 yd³) dump truck loads you need. Confirm with your supplier for exact pricing.
Frequently Asked Questions
How much does fill dirt weigh?
Compacted fill dirt weighs approximately 1,600 kg/m³ (about 1.3 tons per cubic yard). Weight varies by soil type: topsoil is lighter at 1,350 kg/m³, gravel is heavier at 1,800 kg/m³.
What shapes are supported?
Rectangular (length × width), circular (diameter), and triangular (base × height). All shapes require a depth measurement. Choose the shape closest to your project area.
How are truck loads calculated?
The calculator estimates loads using standard dump truck capacities: 10 m³ for metric or 6 cubic yards for imperial. Actual capacity varies by truck — confirm with your supplier.
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil used for grading and filling — it lacks organic matter and does not support plant growth well. Topsoil is the upper layer rich in nutrients, used for landscaping and gardens.
Should I add extra for compaction?
Yes. Fill dirt compresses 10–30% when compacted. Order 15–20% more than the calculated volume to account for settling and compaction.
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