Fill Dirt Calculator
Calculate how much fill dirt you need - enter the area and depth to get the cubic yards and the weight in tons, with a bulk cost estimate for grading, holes and low spots.
United States — national average · 2026 prices
Material only unless stated as installed. Excludes tax, permits and local labour. Verify with local suppliers — see how we calculate.
How this calculator works
Every figure above comes from the formula below, applied to the assumptions listed. Nothing is looked up from a hidden table — you can reproduce the result by hand.
Formula
cubic yards = area (sq ft) × depth (in) ÷ 324
tons = cubic yards × 1.1
coverage per cubic yard = 324 ÷ depth (in), in square feet
Assumptions & limits
- Fill dirt density is taken as 1.1 tons per loose cubic yard, similar to screened topsoil; moisture and clay content move it.
- Fill dirt is unscreened subsoil with no organic matter — which is why it stays stable. It is bought in bulk by the yard or ton; there is no meaningful bagged form, so no bag comparison is shown.
- Bulk price defaults to $15 per cubic yard (typical 2026 range $10–$30), plus a delivery fee that is often $50–$150 and can exceed the dirt cost on small orders.
- Fill compacts below its loose volume: order 10–20% extra, and place deep fills in compacted 6–8 inch lifts rather than one loose dump.
- Structural fills — under slabs, footings or paving — have code compaction requirements, and excavation work near them falls under OSHA trenching rules. This sizes the material, not the geotechnics.
Worked example
Filling a 20 × 10 ft low spot to an average depth of 4 inches
- Area = 20 × 10 = 200 sq ft
- Cubic yards = 200 × 4 ÷ 324 = 2.47 yd³
- Tons = 2.47 × 1.1 = 2.72 tons
- Coverage check: one yard covers 81 sq ft at 4 in — 2.47 × 81 ≈ 200 ✓
Result:2.47 cubic yards (about 2.7 tons) — roughly $31 to $44 of dirt, before delivery.
Built and maintained by Christoph Ballmer, Honeygoat GmbH
Method and constants last checked against the calculator code on August 25, 2026. Independent trade review is not yet in place for this calculator — see how we handle review.
Read the site-wide calculation methodology · estimate vs. quote and safety limits
How much fill dirt do I need?
Fill dirt is bought in bulk by the cubic yard or the ton, and the volume math is the same as every bulk material on this site: area times depth, converted to yards. For grading, estimate the average depth across the area — a low spot that is 6 inches at the center and feathers to nothing at the edges averages about 3 inches.
cubic yards = area (sq ft) × depth (in) ÷ 324 · tons ≈ cubic yards × 1.1
Coverage per cubic yard
| Depth | One yard covers |
|---|---|
| 2 inches | 162 sq ft |
| 4 inches | 81 sq ft |
| 6 inches | 54 sq ft |
| 12 inches | 27 sq ft |
Fill dirt is not topsoil — and that is the point
Fill dirt is unscreened subsoil: no organic matter, no compost, nothing that decomposes. That makes it cheap — typically $10–$30 per cubic yard in 2026, often the cheapest material a truck will bring you — and it is also exactly why it works. Organic matter breaks down and settles for years; subsoil does not. Fill deep holes and build up grades with fill dirt, then cap the top few inches with topsoil where anything needs to grow. Filling a deep hole entirely with topsoil is the classic mistake that turns into an annual sinkhole.
Compaction: order extra, place in lifts
Loose fill settles under its own weight and the first rains. If anything will sit on the fill — a shed, a walkway, a paver patio — place it in 6–8 inch lifts and compact each one, the same discipline the FHWA guide applies to gravel construction. Compacted fill occupies less volume than loose fill, so order 10–20% over the calculated figure. Grading toward the house? Keep the finished surface sloping away from the foundation — fill placed against a wall that traps water causes the problem it was meant to solve.
When delivery costs more than the dirt
On small orders the $50–$150 delivery fee can exceed the material cost, which is why combining a fill order with gravel or topsoil from the same supplier often pays. For odd shapes, the cubic yards calculator converts any dimensions into orderable volume.
Figures are planning estimates — moisture and clay content change the weight per yard, and structural fills under slabs or footings have code compaction requirements. Confirm quantities and delivered pricing with your supplier.
Frequently asked questions
How do you calculate fill dirt needed?
Multiply the area in square feet by the depth in inches and divide by 324 for cubic yards. Filling a 200 sq ft low spot 4 inches deep takes 200 x 4 / 324 = 2.47 cubic yards - about 2.7 tons. For holes, use the hole dimensions; for grading, estimate the average depth across the area.
How much does 1 yard of fill dirt cover?
One cubic yard covers 324 sq ft at 1 inch deep, 108 sq ft at 3 inches, 81 at 4 inches, and 54 at 6 inches. The deeper the fill, the less area a yard covers - and fills deeper than about 8 inches should go in as compacted lifts, not one loose dump.
How much does a cubic yard of fill dirt cost?
Bulk fill dirt is one of the cheapest materials there is: typically $10-$30 per cubic yard in 2026, often less by the truckload, plus a delivery fee that can be $50-$150. It costs less than topsoil because it is unscreened subsoil - no organic matter, no screening step.
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil - free of organic matter, which is exactly why it stays stable and does not keep settling. Use it to fill holes, raise grades and build up around foundations. Topsoil is for the top few inches where things grow. Filling a deep hole with topsoil is a classic mistake: the organics decompose and the fill keeps sinking. Size topsoil with the soil calculator instead.
Does fill dirt need to be compacted?
Yes, if anything will sit on it. Loose fill settles on its own for seasons; compacted in 6-8 inch lifts it becomes a stable base. For structural fills - under slabs, footings or paving - compaction requirements come from the code and, on bigger jobs, a soils report. Order about 10-20% extra, because fill compacts below its loose volume.