Fill Dirt Calculator — cubic yards and tons for filling ground
Enter the area and how much you need to raise it, and get cubic yards and tons — with the loose and compacted soil densities and their sources.
Fill dirt is the least glamorous material in this set and the easiest to get wrong, because unlike aggregate it has no specification at all. It is whatever natural soil the supplier has, and the difference between sandy and clay fill is a factor of about 1.5 in weight.
The densities come from a 2023 Wisconsin Department of Transportation research report that physically measured natural soils across the state, giving separate figures for loose, in-place and compacted conditions. We cross-checked the loose figure against a USDA soil bulk density reference.
The most important caveat is moisture. Every published figure we could find is a dry-weight measurement, and soil sold by the yard contains water. That means the tonnage here is a floor, not a forecast — and we would rather tell you that than quietly under-estimate your order.
A worked example you can check by hand
A 20 ft × 10 ft area at 2 in deep,
with a 5% waste allowance:
Area
200 ft² (20 ft × 10 ft)
Depth
2 in = 0.1667 ft
Volume (before waste)
33.3333 ft³
Waste allowance
5%
Volume (with waste)
35 ft³ = 1.2963 yd³
Density used
77 / 91.5 / 106 lb/ft³ (low / typical / high)
Weight (low)
2,695 lb = 1.3475 short tons
Weight (typical)
3,203 lb = 1.6013 short tons
Weight (high)
3,710 lb = 1.855 short tons
How we calculate this — and every number we used
We do not use a hidden "magic number". Here is the entire calculation:
volume = area × depth
volume_with_waste = volume × (1 + waste%)
weight = volume_with_waste × density
Why a range, not one number? Bulk material density changes with
moisture, gradation and compaction. Publishing a single figure would be falsely precise, so we publish
the range our sources support — and we show you exactly where each number comes from.
Why you can pick the state. The same material weighs very different
amounts loose, in place, or compacted — WisDOT measured volume changes of 27–60% on compaction alone.
Most calculators hide this behind one number. We let you choose.
Topsoil / natural soil — loose (stockpiled), DRY bulk density
How we chose the typical value. WisDOT measured loose dry unit weights of 77–106 pcf across Wisconsin natural soils; the typical is the midpoint of that measured range. USDA NRCS independently gives 83 lb/ft³ (1.33 g/cm³) for a medium-textured soil, which falls inside the range and supports it.
Limits of this constant
CRITICAL: every figure here is a DRY bulk density. Topsoil sold by the cubic yard is moist, typically 10–30% water by mass, so real delivered tonnes can exceed this estimate. We found no authoritative moist topsoil density, so we do not invent one.
"Topsoil" is not a standardised material. WisDOT's natural soils span sandy A-3 to heavy clay CH, a spread of roughly 1.5x.
IN-PLACE density is higher than loose — see the state selector.
How we chose the typical value. WisDOT measured compacted dry unit weights of 116–133 pcf; the typical is the midpoint of that measured range.
Single-source constant. We could only retrieve one authoritative
published figure for this material, so the range may understate real-world variation.
Confirm the figure with your supplier before ordering.
Limits of this constant
DRY bulk density. Whole-number midpoints are our arithmetic, not a source figure.
This calculator is only valid under these assumptions. If any of them do not match your project,
treat the result as a rough guide and get a quote from your supplier.
The area is treated as a rectangle and the ground beneath it is treated as level. For a sloping site, split it into strips and calculate each one.
Depth is how much you want to raise the ground, measured after the soil has settled.
The material is unspecified natural soil. Sand, silt and clay differ by roughly 1.5x in density, and a supplier's 'fill dirt' can be any of them.
The densities are DRY bulk densities. Soil delivered by the yard is moist, so real tonnage is usually higher.
This is not structural fill. Load-bearing fill needs an engineered specification and compaction testing.
Frequently asked questions
How much does a yard of fill dirt weigh?
Loose, about 1.04 to 1.43 short tons per cubic yard on a dry basis; compacted, about 1.57 to 1.8. Heavier clay sits at the top of that range, sandy fill at the bottom.
How much fill dirt to raise my yard?
Multiply area by the depth you want to add, add a waste allowance, and allow for settlement. For 500 square feet raised 12 inches, expect around 21 cubic yards before waste — and order more than the finished volume, because loose fill settles.
Is fill dirt the same as topsoil?
No. Fill dirt is subsoil, used to build up levels; it has little organic matter and is not what you grow plants in. Topsoil is the surface layer. Use fill dirt to raise the ground, then cap it with topsoil where you will plant.
Why does the tonnage look low?
Because every authoritative soil density we found is measured dry, and delivered soil is not dry. If your supplier prices by the ton, ask them for the density of the actual material — that number beats any published average.
Can I use fill dirt under a driveway?
Not without care. Structural fill needs an engineered specification and compaction testing. This calculator is for quantity estimating, not for load-bearing design.