Fill Dirt Calculator
Soil & OrganicMeasurements in, purchasing amount out
How the Fill Dirt Calculator works
The calculator finds volume first, then applies the selected material’s estimated bulk-density range to show weight. Your suggested order adds 10% for settling, uneven ground, and small measurement errors.
Using your measurements
12 ft × 8 ft × (12 in ÷ 12) ÷ 27 = 3.56 cu yd
Density assumption: Unscreened fill dirt · 2,000–2,400 lb/yd³
The full breakdown
How much fill dirt a grading, backfill, or leveling job actually takes
The fill dirt calculator above converts square footage and depth into cubic yards, tons, and bags as you type. Use it to level low spots in a lawn, backfill a retaining wall or foundation, or fill a round hole with the circle shape; getting the volume right up front avoids a second delivery fee and a job that stalls waiting for it.
The critical factor in estimating fill dirt is compaction. Loose soil from a dump truck is full of air. Once it is spread and rolled or tamped in 6-to-8-inch lifts, it shrinks by 15% to 25% to reach its compacted, in-place density. The loose-volume row in the result adds that allowance, so the finished grade does not settle below the target after the first heavy rain.
Fill dirt and topsoil do different jobs. Fill dirt is stable subsoil — minerals, clay, and sand with little organic matter — so it supports weight without rotting or sinking. For lawns and garden beds, use clean fill or select fill to build up the base grade, then finish the top 4 to 6 inches with screened topsoil where grass and plants need to root.
For fill that tapers — a wedge that raises one side of a yard and feathers out to nothing at the other — enter the average depth, which for an even slope is half the deepest point. For a low spot, pull a string line level across it, take depth readings every few feet, and average them.
Soil composition changes weight and tonnage
A cubic yard measures 27 cubic feet of volume, but the weight of fill dirt varies with texture and compaction. Unscreened loose subsoil weighs roughly 2,000 to 2,400 lb/yd³ (1.0 to 1.2 tons), while dense clay or mechanically compacted fill reaches 2,600 to 3,000 lb/yd³ (1.3 to 1.5 tons).
| Fill Dirt | Weight |
|---|---|
| Screened fill | 2,100–2,500 lb/yd³ |
| Clay fill | 2,300–2,800 lb/yd³ |
| Sandy fill | 2,400–2,900 lb/yd³ |
| Compacted in place | 2,600–3,000 lb/yd³ |
Recommended fill depths and compaction lifts
Place fill in sequential 6-to-8-inch layers (lifts), compacting each lift with a plate compactor or roller before adding the next layer to avoid future trench or foundation subsidence.
| Minor lawn depression leveling | 2–4 in (5–10 cm) |
|---|---|
| Patio or paver sub-base grade | 4–6 in (10–15 cm) |
| Foundation & retaining wall backfill | 6–12 in (15–30 cm) per compacted lift |
| Deep hole, pool backfill, or slope raising | 12–36+ in (30–90+ cm), placed in multiple lifts |
Bagged vs. bulk dump truck loads
Small yard repairs and minor leveling can use 40 lb or 50 lb bags from home improvement centers. For major earthmoving, grading, or pool backfilling, bulk delivery in tandem dump trucks (10–14 cubic yards) or tri-axle trucks (14–18 cubic yards) is vastly more cost-effective.
A standard pallet holds roughly 45–60 bags of 40–50 lb bagged fill dirt or soil.
Two ways to compromise a fill dirt project
Failing to compact in shallow lifts
Dumping 12 to 24 inches of loose fill into a hole and running a compactor only over the top leaves uncompacted, fluffy soil underneath. Over time, water infiltration causes deep settling, resulting in sinkholes and cracked overlying structures.
Attempting to plant directly into subsoil fill
Fill dirt lacks the organic matter, beneficial microbes, and nutrient capacity required for healthy root systems. Always cap fill dirt with 4 to 6 inches of screened topsoil before laying sod, seeding grass, or planting shrubs.
Fill dirt, specifically
Fill dirt questions people actually ask
Why add 10% to the calculated amount?
Extra material covers small dips, settling, spillage, and measurements that are not perfectly square. The calculated amount remains visible so you can compare both figures.
Are bag counts based on the same amount?
Both are shown. “Calculated” bags cover the measured volume; “Order” bags include the 10% allowance and round partial bags up to whole bags.
How accurate is the weight estimate?
Volume comes directly from your dimensions. Weight is a range because moisture, particle size, composition, and compaction change bulk density.
What is fill dirt?
Fill dirt is subsoil taken from beneath the top layer of organic soil. It consists of broken-down rock, sand, and clay with virtually no organic matter, making it stable and resistant to decomposing or settling over time.
What is clean fill dirt?
Clean fill dirt is excavated subsoil that is strictly free of organic debris, tree roots, construction trash, asphalt, metal, broken concrete, chemicals, and environmental contaminants.
What is select fill dirt?
Select fill dirt is engineered, screened soil containing a specifically tested balance of clay, sand, and aggregate designed to achieve maximum density and load-bearing strength under building foundations, concrete slabs, and roadways.
Where to buy bags of fill dirt?
You can buy bags of fill dirt, topsoil, and leveling soil in 40 lb to 50 lb bags at home improvement centers (such as Home Depot, Lowe’s, and Menards), local garden nurseries, and landscape supply centers.
How much does fill dirt cost?
Bulk fill dirt generally costs $10 to $30 per cubic yard picked up, or $15 to $40 delivered, depending on region, soil quality, and haul distance. Screened clean fill runs $20 to $35 a yard and certified select fill $25 to $45 before delivery. Bagged fill costs far more — $3 to $6 per 50 lb bag, or $60 to $120 per cubic yard equivalent — which is why a truckload wins past a small patch.
How much fill dirt do I need?
Multiply length by width in feet to get square feet, multiply by depth in feet (depth in inches ÷ 12), and divide by 27 to find cubic yards. Then add 15% to 25% extra to account for mechanical compaction and settling.
What is fill dirt used for?
Fill dirt is used to raise ground elevation, fill low spots and sinkholes, backfill around foundation walls and retaining walls, build driveway and patio sub-bases, and create proper drainage slopes away from structures.
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil: mineral, low in organic matter, and stable, so it compacts and stays put under a patio, a slab, or a raised grade. Topsoil is the dark upper layer that holds the organic matter and nutrients plants need, and it settles and breaks down if it is used as structural fill. Use fill to build up depth, then cap it with 4 to 6 inches of topsoil wherever something has to grow — the topsoil calculator sizes that layer.
Where can I get free fill dirt?
Excavation contractors, pool builders, and road crews often need to get rid of spoil and will deliver it free, and local listing sites connect them with people who want it. The catch is what is in it. Ask for clean fill — no concrete, asphalt, trash, or organic debris — and ask where it came from, because soil from old industrial or roadside sites can carry contaminants. Free fill is fine for raising grade under a lawn; it is a poor bet under a slab or anywhere it has to compact predictably.
How much is a load of fill dirt?
A delivered dump truck load of fill dirt usually costs between $200 and $600. Single-axle trucks deliver 5–7 cubic yards, standard tandem trucks carry 10–14 yards, and large tri-axle trucks hold 14–18 cubic yards.
How much does a yard of fill dirt weigh?
A cubic yard of typical fill dirt weighs between 2,000 and 2,600 pounds (1.0 to 1.3 tons) loose, and can weigh up to 2,800 to 3,000 pounds (1.4 to 1.5 tons) when densely compacted or damp.