Fill Dirt Calculator

Calculate the volume, weight and number of dump-truck loads of fill dirt, topsoil, sand, gravel or crushed stone you need to order.

Dimensions

Area shape
ft
ft
ft
6 in = 0.5 ft · 30 cm = 0.3 m
Default 1.25 = 25 % extra over hole volume.
yd³
Common tri-axle: 14 yd³ (~10.7 m³).
$

Calculation results

Volume to order

— yd³

Total weight

— tons

Dump-truck loads

— loads

Results include the specified compaction factor. Densities are typical averages — confirm with your supplier for orders over 50 yd³.

Informational only. These results are estimates for planning and ordering. For critical, load-bearing or life-safety applications, consult a licensed professional who can verify site conditions, code requirements and material specifications.

Understanding the formula

Three short calculations turn dimensions on a drawing into a delivery order. Volume comes from the footprint area times the depth, the compaction factor adds the extra you need to order, and density turns volume into weight.

V = area × depth · ordered = V × compaction · weight = ordered × density

Area equals L × W for a rectangle, π × r² for a circle and 0.5 × base × height for a triangle. The number of truckloads is ceil(ordered / truck capacity), and the cost (when entered) is ordered × price per cubic yard or cubic metre.

Worked example

A 10-ft × 10-ft pad, six inches deep, in loose fill dirt:

  • Volume = 10 × 10 × 0.5 = 50 ft³ ≈ 1.85 yd³
  • Ordered = 50 × 1.25 = 62.5 ft³ ≈ 2.31 yd³
  • Weight = 2.31 × 2,200 = 5,093 lb ≈ 2.55 tons
  • Truckloads = ceil(2.31 / 14) = 1

When to use this calculator

Use it any time you need to order loose material by the truckload:

  • Driveway prep: crushed stone or gravel base under a new gravel or paver driveway.
  • Foundation backfill: returning soil around a poured wall once forms come off.
  • Raised garden beds: topsoil for vegetable boxes and landscape mounds.
  • French drains: clean gravel bedding around a perforated pipe.
  • Slope correction: adding fill to grade a low spot away from a building.
  • Pad preparation: compacted fill under a slab, deck or shed.

The calculator does not size retaining walls, slopes or drainage — those need site-specific engineering. It also doesn’t subtract the volume taken up by pipes, footings or other obstructions inside the fill area; deduct those by hand if they’re significant.

Common mistakes & tips

  • Don’t order by hole volume alone. Skipping the compaction factor is the most common error — you end up two truckloads short on a one-day pour.
  • Ask your supplier for the actual density. Default values are conservative averages. Wet dirt can run 10–15 % heavier; dry sand ~10 % less.
  • Round up truckloads. A half-load usually costs the same as a full one — take the truck and stockpile the remainder.
  • Mind the difference between “fill dirt” and “structural fill”. Generic fill dirt is fine for landscape grading; under a foundation you usually need engineered fill with documented density.
  • Measure depth twice. A small change in depth has the same effect as a big change in length × width.

Frequently asked questions

How accurate is the fill dirt calculator?
The geometry is exact. The accuracy of the order depends on the depth measurement (small errors multiply across the area) and the density of the material your supplier delivers. For orders over 50 yd³, ask the supplier for their measured density.
What is the difference between loose and compacted fill dirt?
“Loose” means dirt as it sits in the dump truck, with air gaps between particles. “Compacted” means dirt after machine compaction, weighing about 25–30 % more per cubic yard.
How much does a yard of fill dirt weigh?
Loose fill dirt averages 2,200 lb per cubic yard (about 1.1 tons). Compacted fill dirt averages 2,800 lb per cubic yard (1.4 tons).
Why do I need a compaction factor of 1.25?
Loose material settles when it dries, when it is walked on, or when it is intentionally compacted. The 1.25 factor reflects a typical 25 % volume loss from delivery to final-grade. Use 1.10–1.15 for clean uniform sand, 1.30–1.40 for wet structural fill.
How many cubic yards fit in a dump truck?
A standard tri-axle dump truck carries about 14 yd³ (10.7 m³). Smaller single-axle dumps haul 8–10 yd³; larger dump trailers haul 16–20 yd³.
Can I use this for topsoil, sand, gravel or crushed stone?
Yes — pick the material in the dropdown. Each option ships with its own density (topsoil 2,000 lb/yd³, sand 2,700, gravel 2,800, crushed stone 2,700). The geometry and compaction logic is identical.
How do I figure out the volume of an irregular hole?
Break it into rectangles, circles and triangles, calculate each piece, and sum the results. For curved or sloping shapes, average the depth at several points and use that as the input depth.
Does the calculator account for waste during delivery?
Indirectly — the compaction factor covers most settling and minor spillage. For long hauls or steep dump sites, add another 5–10 % to the compaction factor.