Materials
Fill Dirt Calculator
Fill volume in place, and how much loose material to order once compaction is allowed for.
Fill needed in place
cubic yards
- Loose volume to order
- —cu ydAdd a compaction allowance to see how much loose material to order. Compacted fill always takes more than its finished volume.
- Cubic feet in place
- 750cu ft
- Cubic metres in place
- 21.24m³
- Area covered
- 1,500ft²
This is the finished, compacted volume. Order this much loose and you will come up short — add your compaction allowance to get the delivery quantity.
The working
Area = Length × Width
= 50 ft × 30 ft
= 1,500 ft²
Compacted volume = Area × Depth
= 1,500 ft² × 0.5 ft
= 27.78 cu yd
Compacted fill always takes more loose material than its finished volume — the opposite direction to excavation swell, and the usual reason a fill order comes up short. Enter the area and the finished depth for the in-place volume; add your compaction allowance to get the delivery quantity.
How this calculator works
- Formula version
- 1.0.0
- Last reviewed
- 2026-09-01
- External data
- None
This tool uses only your inputs and exact unit conversions. No benchmark, average or market figure is built into it. How we calculate
What this calculates
Two quantities that are often confused. First, the compacted volume the fill occupies once it is in place and finished. Second, the larger loose volume you have to buy for that to happen — but only if you supply a compaction allowance.
Shrink runs the opposite way to swell
Excavation swell describes material leaving the ground: dug soil is looser than it was in place, so a hole yields more loose yards than its geometric volume.
Fill runs the other way. Loose material delivered to site is compacted down into a smaller finished volume, so you always need more loose yards than the finished volume you measured. Applying swell here, or nothing at all, is how a fill order comes up short.
Uniform and tapered fills
A uniform fill is area times depth. A fill that tapers evenly from a deep edge to nothing is exactly half that, because it is a wedge rather than a prism — the calculator applies the halving and shows it in the working.
Why the compaction allowance is yours to supply
It depends on the soil, its moisture at placement, the lift thickness and the compactive effort actually achieved. A structural fill compacted to a specified density behaves differently from a yard levelled with a plate compactor.
The honest sources are a geotechnical report or your supplier. No default is shipped, and the calculator says plainly when the figure is missing rather than quietly leaving it out.
Worked example
A 50 ft × 30 ft area filled 6 in deep, with a 25% compaction allowance
- Length
- 50 ft
- Width
- 30 ft
- Finished depth
- 6 in
- Compaction allowance
- 25% (entered by the user)
- Area= 50 ft × 30 ft= 1,500 sq ft
- Compacted volume= 1,500 sq ft × 0.5 ft= 750 cu ft
- Cubic yards in place= 750 ÷ 27= 27.8 cu yd
- Loose to order= 27.8 × 1.25= 34.7 cu yd
- Constant depth for a uniform fill; an even taper to zero for a tapered one.
- The finished depth entered is the depth after compaction.
- The compaction allowance is expressed as extra loose volume over the compacted volume.
- Unit conversions are exact.
- It does not assume a compaction or shrink factor. Without one it reports the in-place volume only.
- It does not model irregular terrain. For a site with varying cut and fill across it, the cut and fill calculator uses a grid of elevations instead.
- It does not assume a density, so it cannot give tons on its own.
- It does not verify that your fill material is suitable for a structural application.
Common questions
- Why do I need more fill dirt than the volume of the hole?
- Because loose material compacts. The volume you measure is the finished, compacted volume; the material arrives loose and consolidates as it is placed and rolled. Order only the finished volume and you will run short.
- What compaction percentage should I use?
- This calculator will not guess one, because it depends on your soil, its moisture, the lift thickness and the compaction actually achieved. A geotechnical report or your supplier is the honest source. Without it you still get the in-place volume.
- Is compaction the same as swell?
- They are opposites. Swell describes material expanding as it leaves the ground, which matters when you are hauling spoil away. Compaction describes material shrinking as it is placed, which matters when you are buying fill.
Where people go next
All materials tools →Ordered by what usually comes next in the same job, not by keyword.