How to Calculate Cubic Yards of Dirt, Fill Volume & Truckloads

On an earthwork job, the fastest way to blow a budget is to order the wrong amount of dirt. Order short and you pay for a second delivery, remobilize equipment, and stall the schedule. Order long and you are stuck with a stockpile you paid for, plus haul-off fees if the site cannot absorb the excess. For contractors, the difference between a profitable grade job and a money-losing one often comes down to knowing how to calculate cubic yards of dirt before the first truck rolls.

Fill volume estimating is not complicated, but it does require discipline. You need accurate dimensions, a consistent unit of measure, and a clear understanding of how material behaves once it is placed and compacted. A common mistake is treating a cubic yard in the bank as equal to a cubic yard in the truck and a cubic yard in the fill. They are not the same, and ignoring that gap is how contractors end up 15 to 25 percent short on structural fill.

This guide walks through the full estimating workflow used by working earthwork contractors: measure the site, compute volume in cubic yards, account for cut-and-fill balance, adjust for compaction and settlement, convert volume to tons, and translate the result into truckloads. Whether you are backfilling a foundation, building a driveway pad, or leveling a building lot, the same process applies. When you are ready to source material, you can browse fill dirt listings on NeedsDirt.com and compare local suppliers and dump sites by price and haul distance.

Rule of thumb: If your fill is structural and will be compacted to 95 percent, order at least 20 percent more loose volume than the geometric volume of the hole.

We will also cover the questions most guides skip: how to handle sloped sites, how to convert between cubic yards and tons for different soil types, and how many cubic yards actually fit in a dump truck or dump trailer. By the end, you should be able to produce a defensible quantity takeoff that your foreman, your supplier, and your client can all trust.

The basic formula for volume is length times width times depth. The only trick is keeping units consistent and converting to cubic yards at the end. One cubic yard is 27 cubic feet, or a cube 3 ft by 3 ft by 3 ft. All your measurements should be in feet, then divided by 27.

For a rectangular fill area:

• Measure length in feet.
• Measure width in feet.
• Measure or specify depth in feet (convert inches by dividing by 12).
• Multiply length x width x depth to get cubic feet.
• Divide by 27 to get cubic yards.

Example: A pad 40 ft long, 30 ft wide, and 6 in. deep. Depth in feet is 0.5. Volume = 40 x 30 x 0.5 = 600 cubic feet. 600 / 27 = 22.2 cubic yards.

For circular areas, such as a round patio base or a tree pit, use pi times radius squared times depth. If the radius is 6 ft and depth is 1 ft, volume = 3.1416 x 36 x 1 = 113.1 cubic feet, or 4.19 cubic yards.

For triangular areas, multiply base times height times depth, then divide by 2. For irregular shapes, break the area into rectangles, triangles, and circles, calculate each, and sum the results. Many contractors sketch the site on graph paper or use a simple CAD or takeoff app to avoid arithmetic errors.

Sloped sites need extra care. If a fill pad must be level but the existing ground slopes, compute the average depth by taking several depth readings across the area and averaging them. Better yet, divide the pad into strips or a grid, calculate each cell, and add them up. This grid method is standard practice for cut-and-fill estimates on building lots.

Always add a waste or shrinkage allowance before you finalize the number. For granular fill, 5 to 10 percent is typical. For clay-heavy or rocky material, 10 to 15 percent. For structural fill that will be compacted, use the compaction adjustment covered later in this guide. A dirt calculator cubic yards tool can speed up the math, but you still need to verify the inputs and apply the right adjustment factors. When you know your target volume, find fill dirt on NeedsDirt.com to compare local sources by volume, price, and haul distance.

Most sites are not pure fill jobs. You cut in some areas and fill in others. The net dirt needed is total fill volume minus total cut volume, adjusted for how the cut material behaves when placed. If cut exceeds fill, you have export material and may need a dump site. If fill exceeds cut, you need import fill dirt.

To estimate cut volume, use the same geometric formulas, but measure the existing grade and the proposed grade. The difference is the cut depth. For example, if you are lowering a 50 ft by 40 ft area by 2 ft, cut volume is 50 x 40 x 2 = 4,000 cubic feet, or 148.1 cubic yards in the bank.

Cut material in the bank is denser than the same material after excavation. A cubic yard in the bank typically swells to 1.15 to 1.35 cubic yards loose, depending on soil type. Sand and gravel may swell 10 to 15 percent, while clay can swell 25 to 35 percent. That means 100 cubic yards of cut clay might produce 125 to 135 loose cubic yards, which can be moved and compacted into roughly 90 to 100 cubic yards of compacted fill. The exact numbers depend on the soil and the compaction specification.

Here is a practical cut-and-fill workflow:

• Calculate total cut volume in the bank.
• Apply a swell factor to get loose volume available for hauling.
• Calculate total fill volume in its final compacted state.
• Apply a compaction factor to determine how much loose material is needed.
• Subtract available cut material from required fill material to find the net import or export.

Example: You need 500 cubic yards of compacted fill. Your cut produces 400 bank cubic yards of sandy loam. Swell factor of 1.15 gives 460 loose cubic yards. If that material compacts at 90 percent, it may yield about 414 compacted cubic yards. Net import needed is roughly 86 cubic yards, plus a waste allowance. That is a very different number than the naive 100 cubic yards you would get by subtracting bank yards from fill yards.

On balanced sites, contractors try to match cut and fill to avoid hauling costs. But balanced volumes are rare because soil type, compaction, and grade tolerances rarely cooperate. If you end up with export material, browse dump sites near you on NeedsDirt.com. If you need import, compare fill dirt listings in your area to keep haul costs down.

Compaction is the single biggest reason contractors come up short on fill. When you place loose dirt and run a plate compactor or roller over it, the material densifies. The volume shrinks. If you ordered only the geometric volume of the hole, you will not have enough material to reach final grade after compaction.

Compaction is usually specified as a percentage of maximum dry density, determined by a Proctor test. Common specifications are 90 percent, 95 percent, and 98 percent. The higher the percentage, the more material you need because the final compacted volume is denser. A good estimating rule is to divide the required compacted volume by a compaction efficiency factor.

For example, if you need 100 cubic yards of compacted fill at 95 percent compaction, and your loose material compacts to about 85 percent of its loose volume, you need roughly 100 / 0.85 = 117.6 loose cubic yards. Add a 5 percent waste factor and you are at about 123.5 cubic yards to order.

Settlement is a related but separate issue. Even well-compacted fill can settle slightly over time, especially if it is placed over soft subgrade or contains organic material. For structural fills under slabs or footings, geotechnical engineers often require over-excavation and replacement with engineered fill. For landscaping and non-structural fills, a 5 to 10 percent over-order is cheap insurance.

Practical adjustments by material type:

• Clean sand and gravel: 10 to 15 percent shrinkage from loose to compacted.
• Sandy loam: 15 to 20 percent.
• Clay: 20 to 30 percent, and it can be difficult to compact in wet conditions.
• Crushed stone: 10 to 20 percent, depending on gradation.

Always ask your supplier or the geotech report for a shrinkage or compaction factor. If you cannot get one, use a conservative 20 percent for mixed soil and 25 percent for clay. Then verify with a test strip or a nuclear gauge on site. The cost of a few extra yards is far less than the cost of a failed compaction test or a settled slab.

When ordering on NeedsDirt.com, confirm whether the listed volume is bank, loose, or compacted cubic yards. Most listings quote loose volume, but it pays to ask. A quick conversation with the seller can prevent a costly misunderstanding.

Suppliers often price fill dirt by the ton, while contractors estimate by the cubic yard. To compare apples to apples, you need a conversion. The bridge is bulk density, usually expressed in tons per cubic yard.

Typical bulk densities for common materials:

• Topsoil: 1.0 to 1.3 tons per cubic yard.
• Sand: 1.2 to 1.4 tons per cubic yard.
• Gravel: 1.3 to 1.6 tons per cubic yard.
• Clay: 1.3 to 1.6 tons per cubic yard.
• Crushed stone: 1.35 to 1.55 tons per cubic yard.

Example: You need 100 cubic yards of sand. At 1.3 tons per cubic yard, that is 130 tons. If the supplier charges $18 per ton, the material cost is $2,340. If another supplier quotes $28 per cubic yard, that is $2,800. The ton price is lower, but you also need to factor hauling, minimum loads, and delivery fees.

Truckload capacity varies widely:

• Pickup truck: 1 to 2 cubic yards, depending on bed size and weight limits.
• Dump trailer: 4 to 8 cubic yards.
• Single-axle dump truck: 8 to 12 cubic yards.
• Tandem-axle dump truck: 12 to 16 cubic yards.
• Tri-axle dump truck: 16 to 20 cubic yards.
• Semi end dump: 20 to 25 cubic yards.

Weight limits matter as much as volume. A tandem-axle dump truck can legally haul about 15 to 17 tons on most roads. If your material weighs 1.5 tons per cubic yard, that truck can only carry about 10 to 11 cubic yards before it is overweight. Always calculate both volume and weight, and use the lower number.

To estimate truckloads, divide your total loose volume by the usable capacity per truck. If you need 120 loose cubic yards and each tandem carries 12 cubic yards, that is 10 loads. Add one load for waste and scheduling buffer. On NeedsDirt.com, many listings include truck capacity and delivery radius, which makes it easier to estimate total delivered cost. Compare the cost per delivered cubic yard, not just the material price, to find the best value.

Pro tip: Ask the hauler for the truck's legal payload in tons and the material's density. Then calculate loads by weight first, volume second. That is how you avoid overweight fines and short loads.

Even experienced contractors make estimating errors when they rush. Here are the most common mistakes and how to prevent them.

1. Mixing units. Depth in inches, length in feet, and width in yards is a recipe for disaster. Convert everything to feet before multiplying, then divide by 27. Write the units next to every number in your takeoff.

2. Forgetting compaction. As covered earlier, loose dirt shrinks when compacted. If you order the geometric volume of the hole, you will be short. Apply a compaction factor of 15 to 25 percent for most soils.

3. Ignoring swell. Cut material expands when excavated. If you are balancing cut and fill, you cannot compare bank cubic yards directly to compacted cubic yards. Apply a swell factor to cut and a compaction factor to fill.

4. Using the wrong density. Sand, clay, and gravel have different tons-per-yard values. Using a generic 1.5 tons per cubic yard can throw your tonnage off by 20 percent or more. Get the actual density from the supplier or a soil test.

5. Overlooking access and haul distance. A cheap source 40 miles away may cost more in hauling than a slightly more expensive source 10 miles away. Calculate cost per delivered cubic yard, including fuel, driver time, and traffic.

6. Not verifying grade. Existing grade is rarely as flat as it looks. Take multiple depth readings and average them. On large sites, use a laser level or GPS machine control to build an accurate surface model.

7. Forgetting waste and spillage. Add 5 to 10 percent for handling losses, especially with loose sand and gravel. It is better to have a small stockpile left over than to pay for a second delivery.

8. Assuming all fill is the same. Structural fill under a foundation must meet engineering specs. Topsoil is for landscaping. Do not substitute one for the other without approval. If you need specific material, filter your search on NeedsDirt.com by material type and location.

Finally, document your calculations. A simple spreadsheet with length, width, depth, volume, compaction factor, and truckloads will save you time on the next job and give you a defensible record if a client questions the quantity. Review your actual vs. estimated usage after each job and adjust your factors. Over time, you will build a reliable estimating system tailored to your region and soil conditions.