Fill Dirt Calculator
Cubic yards and tons of fill dirt for raising grade, backfilling and building up low areas.
Quick estimating rule of thumb
For fill dirt: length (ft) × width (ft) × depth (in) ÷ 324 = cubic yards. Fill is about 1.25 tons per yard and is sold by the yard or the ton. Deep fills settle for months, so order 10–15% extra and compact in 6-inch lifts rather than dumping it all at once.
This fill dirt calculator converts an area and depth into the cubic yards and tons of fill dirt required to raise the grade around a foundation, build up a low spot, backfill a pool or trench, or create a berm.
Fill dirt is subsoil with little or no organic matter, so it compacts and stays put rather than settling and growing weeds like topsoil. It is ordered loose and compacts by roughly 10 to 25%; the tool adds a 10% allowance.
Fill dirt vs topsoil
Fill dirt goes on the bottom. It is structural, cheap, and does not decompose. Topsoil goes on top, the last 4 to 6 inches, for anything you will plant or seed. Filling a large area, you place and compact fill dirt to within 4 to 6 inches of final grade, then cap it with topsoil.
Use the topsoil calculator for that final layer.
Compact as you go
Dumped in one pile and left, fill dirt settles for years and takes structures and pavement down with it. Place it in 6 to 8 inch lifts and compact each one, especially near foundations and under anything that will be paved. Slope finished grade away from buildings at least 6 inches over the first 10 feet.
One cubic yard of fill covers about 160 square feet at 2 inches, or 54 square feet at 6 inches.
Ordering and weight
Fill dirt is sold by the ton or cubic yard; a cubic yard weighs about 1.25 tons dry and considerably more wet. It is the cheapest soil product, and some excavators will deliver clean fill free to get rid of it. Order 10 to 15% extra to cover compaction.
Common fill-dirt mistakes
Dumping it in one pile. Fill must go in 6–8 inch lifts, each compacted, or it settles for years and cracks whatever sits on it.
Using it as growing medium. Fill dirt has no organic matter. Cap it with topsoil for lawns and beds.
Grading toward the house. Finished fill must slope away from foundations, at least 6 inches over the first 10 feet.
Not checking for clean fill. Confirm the source is free of debris, concrete and contaminants, especially near gardens.
| Material | lb / ft³ | tons / yd³ | Sold by | Typical use |
|---|---|---|---|---|
| Screened topsoil (dry) | 75–85 | 1.10 | yd³ (some ton) | New lawns, bed top-up, levelling |
| Topsoil (moist) | 95–110 | 1.40 | yd³ | As delivered after rain; weighs more |
| Fill dirt / structural fill | 90–100 | 1.25 | ton or yd³ | Raising grade, backfill, berms |
| Compost | 40–50 | 0.55 | yd³ or bag | Bed amendment, lawn top-dressing |
| Garden / raised-bed mix | 65–80 | 1.00 | yd³ or bag | Filling raised beds (soil + compost blend) |
Background reading: cubic yards to tons chart.
Frequently asked questions
How much fill dirt do I need?
Multiply area by depth and divide by 27 for cubic yards. A 400 square foot area raised 6 inches needs about 7.4 cubic yards loose, plus 10 to 15% for compaction.
How many tons of fill dirt in a cubic yard?
About 1.25 tons dry; wet clay fill can reach 1.5 tons or more per cubic yard.
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil with no organic matter. It compacts and stays stable, used for structural fill. Topsoil is the organic-rich top layer used for growing plants.
Does fill dirt need to be compacted?
Yes, in 6 to 8 inch lifts, especially near foundations and under future pavement. Uncompacted fill settles for years.
How much does fill dirt cost?
It is the cheapest soil, often $8 to $20 per cubic yard delivered, and sometimes free from excavation sites needing to offload clean fill.
Can I use fill dirt to grow grass?
Not directly. Bring the grade up with compacted fill dirt, then cap it with 4 to 6 inches of topsoil before seeding or sodding.
How much fill dirt to level a yard?
Measure the average depth needed across the area, often just 1 to 3 inches for levelling. A 1,000 square foot yard at 2 inches average needs about 6 cubic yards.
How is fill dirt sold?
By the cubic yard or the ton, delivered by dump truck. A tandem truck holds 10 to 14 cubic yards.
How many cubic yards of fill dirt in a dump truck?
A tandem dump truck carries 10 to 14 cubic yards of fill; a tri-axle 16 to 18.
Is fill dirt cheaper than topsoil?
Much cheaper, often $8 to $20 per cubic yard delivered, and sometimes free from nearby excavation sites that need to offload clean fill.
How much fill dirt to raise a yard 6 inches?
About one cubic yard covers 54 square feet at 6 inches. A 1,000 square foot area needs roughly 19 cubic yards loose, plus a compaction allowance.
Can I use fill dirt around a foundation?
Yes, compacted in lifts and graded to slope away from the wall. Keep it several inches below siding and weep holes.
What is the difference between fill dirt and structural fill?
Structural fill is fill dirt that has been tested and placed to an engineered compaction spec under footings or pavement. Ordinary fill dirt is the same material without the testing.