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 Used:
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, or 4 at 6 yd³ each
Soil Types and Weight
The five soil types change only the weight. With the example above, the same 15 m³ comes to 20.25 t as topsoil and 27 t as gravel, so picking the closest type matters when you order by the ton. Fill dirt is subsoil, the layer under the topsoil, while topsoil is the darker, organic top layer used for gardens and lawns.
Accounting for Compaction
Soil is dug and delivered loose and then compacted where it goes, and compacted soil fills less space than the same soil loose. The calculator gives the volume of the space to be filled, which is the compacted figure, so ordering exactly that volume of loose soil leaves you short. How much extra you need depends on the soil and the compaction method; on structural fill, the engineer's specification sets the standard to meet.
Truck Load Estimates
The two truck lines divide the volume by 10 m³ and by 6 cubic yards (about 4.59 m³) and round up, with the exact number of loads in brackets. A real truck's capacity depends on the vehicle and on the load, so check it with whoever delivers before you book.
Measuring Uneven Ground
If the depth changes across the area, measure it at several evenly spaced points and enter the average. Where the ground slopes evenly from one edge to the other, the average of the two edge depths gives the same volume. Irregular sites are easier to split into rectangles and triangles, each calculated on its own.
Tips & Recommendations
The result is the volume of the space. Soil shrinks when compacted, so agree the extra amount with your supplier.
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 its own density for the weight estimate. Choose what matches your project.
See how many 10 m³ or 6 yd³ loads you need, rounded up to whole trucks. Confirm sizes and prices with your supplier.
Frequently Asked Questions
How much does fill dirt weigh?
This calculator uses 1,600 kg/m³ for fill dirt, about 1.35 short tons per cubic yard, along with 1,350 for topsoil, 1,550 for sand, 1,800 for gravel and 1,750 kg/m³ for clay. Real soil varies with moisture and with how tightly it is packed, so a supplier's figure for its own material is the better one to use.
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 volume is divided by 10 m³ for one line and by 6 cubic yards for the other, and each is rounded up to whole loads. Both sizes are assumptions; real trucks vary, so confirm the capacity 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?
Usually, yes. Loose soil fills less room once it is compacted, so a delivered load covers less than its own volume. The amount depends on the soil and on how it is compacted, and the calculator adds nothing, so agree the extra with your supplier or engineer.
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