Formula
In-place volume is the finished hole: area times depth. A rectangle is length × width. A circle is π × (diameter ÷ 2)². A triangle is ½ × base × height. Cubic yards are cubic feet ÷ 27. A second area is added before the allowance.
fill, loose yards = in-place yards × (1 + compaction ÷ 100)
order = loose yards, rounded up to the next ½ yd³
dig, loose yards = bank yards × (1 + swell ÷ 100)
tons = loose yards × pounds per yard ÷ 2,000
trucks = ceil(loose yards ÷ truck)
A 20 × 10 ft pad, 6 in deep, is 100 ft³, or 3.7 yd³. At 20% compaction the loose order is 4.44 yd³, which the supplier half-yard rounds to 4.5. Weight uses the unrounded loose yards: 4.44 tons at 2,000 lb/yd³. One 10-yard truck. Compact fill in lifts of about 4 to 6 inches. This percent is not a tested Proctor density.
Digging swells the bank. A 30 × 20 ft cut, 1 ft deep, is 22.22 bank yards. At 25% swell the loose pile is 27.78 yards, which is three 10-yard trucks. An irregular grade is several rectangles or triangles added together. About 6 wheelbarrow loads make a cubic yard if the barrow is 4.5 ft³. Fill dirt is not topsoil. Planting soil is the soil calculator.
Worked examples
20 × 10 ft, 6 in, 20% compaction, 2,000 lb/yd³. 3.7 yd³ in place. Loose 4.44 yd³, order 4.5 yd³, 4.44 tons, 1 truck.
12 ft circle, 4 in, 0% compaction. Area about 113.10 ft². Volume about 37.70 ft³, or 1.396 yd³.
3 × 3 × 3 ft hole, 25% compaction, 2,400 lb/yd³. 1.000 yd³ in place, 1.25 loose yards. The half-yard order is 1.5 yd³. Weight uses the loose yards: 1.50 tons.
Dig 30 × 20 ft, 1 ft deep, 25% swell, 10 yd³ truck. 22.22 bank yards, 27.78 loose yards, 3 trucks.
Reference
Planning presets. The supplier’s weight and the truck’s legal payload replace the row.
| Preset | Value | Use |
|---|---|---|
| Lightly tamped | 10% | Compaction allowance |
| Compacted in lifts | 20% | Default fill allowance |
| Heavy or clay | 25–30% | Compaction allowance |
| Sand or gravel swell | 12% | Dig-out |
| Common earth | 25% | Default dig-out |
| Clay swell | 35% | Dig-out |
| Rock or shale | 50% | Dig-out |
| Dry loose fill | 2,000 lb/yd³ | About 1.00 ton |
| Moist fill | 2,400 lb/yd³ | About 1.20 ton |
| Clay-heavy fill | 2,700 lb/yd³ | About 1.35 ton |
Questions
How much fill dirt do I need for a 20×20 area?
At 6 inches of finished depth and 20% compaction, 20 × 20 × 0.5 ft is 7.41 cubic yards in place and 8.89 loose yards, which rounds up to 9 yards to order. Change the depth and the compaction percent for your grade.
How much does a yard of dirt weigh?
This page defaults to 2,000 lb, about 1.00 ton, for dry loose fill. Moist fill is set at 2,400 lb and clay-heavy fill at 2,700 lb. Those are planning figures. Ask the supplier what their yard weighs if a truck or trailer has a payload limit.
How many yards are in a dump truck?
The presets are 5 cubic yards for a single axle, 10 for a tandem, and 14 for a tri-axle. That is a loose-yard planning count, not a legal payload. A truck that holds 10 yards of dry fill may be overweight with moist clay.
How much does fill dirt compact?
Loose dumped fill settles when it is compacted. This page adds 10% for a light tamp, 20% for compaction in lifts, and 25 to 30% for a heavy clay. The percent is editable. It is not a Proctor density.
What is the difference between fill dirt and topsoil?
Fill dirt is for raising a grade, filling a hole, or backfill. Topsoil is the planting layer. Garden beds and lawn topdressing belong on the soil calculator. Do not plant in raw fill and expect a lawn.
How many wheelbarrows are in a yard of dirt?
A common contractor wheelbarrow is about 4.5 cubic feet. 27 ÷ 4.5 is 6 loads per cubic yard. That is approximate. The wheelbarrow you own may be smaller.
Is fill dirt sold by the ton or the yard?
Both. Many yards sell by the cubic yard and also quote a ton price. This page shows the loose yards and the tons at the density you enter. The ticket is the sale.
Sources
- Volume is ordinary geometry. One cubic yard is 27 cubic feet. One cubic metre is 1.308 cubic yards, from 0.3048 metres per foot.
- Swell presets are planning midpoints in the bands published in earthmoving handbooks, including the Caterpillar Performance Handbook material tables: sand and gravel near 12%, common earth near 25%, clay near 35%, rock or shale near 50%. They are typical, not a transcribed cell from one edition, and the field is editable.
- Loose unit weights of 2,000, 2,400, and 2,700 lb/yd³ are planning figures in the range extension publications and highway borrow tables use for dry fill, moist fill, and clay. Moisture and clay move the real weight. The supplier’s per-yard weight wins.
- Topsoil and a settle allowance for a planting bed are the soil calculator. Stone is the gravel calculator.