Fill Dirt Calculator
Estimate fill dirt in cubic yards and tons for grading, backfill, and foundation prep.
Your Fill Dirt Estimate
- Measure the area — length and width of the space to fill.
- Determine depth — how deep the fill needs to be. For uneven ground, use the average depth.
- Adjust density — 110 lb/ft³ for compacted fill. Loose fill is lighter (~90 lb/ft³).
- Use 15% waste — fill dirt compacts 15–25% — loose fill settles significantly.
- Specify clean fill — tell your supplier if you need "clean fill" (no debris, rocks, or organic material).
Estimating Fill Dirt Correctly
Fill dirt is sold by the cubic yard. The biggest mistake people make is forgetting the compaction factor — loose fill dirt compacts to about 75–85% of its delivered volume. If you need 10 cubic yards of compacted fill in place, order 12–13 cubic yards to account for compaction. The 15% waste factor in the calculator covers this.
Fill dirt is one of the cheapest bulk materials — often $5 to $15 per cubic yard at the source, plus delivery ($50–$150 per load). Some excavation sites give away clean fill for free if you haul it yourself. Always ask what's in the fill — "clean fill" means no organic material, trash, or contamination.
Fill Material Types
Not all fill is the same. Choose the right type for your project:
| Material | Density (lb/ft³) | Cost/Yard | Best For |
|---|---|---|---|
| Clean fill dirt | 110 | $5–$15 | General fill, backfill, grading |
| Structural fill | 120 | $15–$25 | Under foundations, roads, load-bearing |
| Screened fill | 105 | $10–$20 | Landscaping, raised beds, final grade |
| Sand fill | 100 | $20–$35 | Drainage, leveling, under slabs |
| Clay fill | 125 | $5–$15 | Compacts well but drains poorly |
For foundation backfill and structural applications, your engineer may specify a particular fill type and compaction requirement (typically 95% Proctor density). Non-structural fill for landscaping is less critical.
Formulas
Simple volume calculation with compaction factor:
Cubic yards = Volume ÷ 27
Weight (tons) = Volume × Density ÷ 2,000
With compaction/waste = Cubic yards × (1 + Waste %)
The waste/compaction factor is critical for fill dirt. Loose fill compacts 15–25%. A 15% factor is conservative for most projects.
Related Calculators
Fill dirt raises the grade — then add topsoil or gravel on top. Browse our landscaping calculator collection for more tools.
Frequently Asked Questions
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil — it contains no organic matter and is used for building up grade, backfilling, and structural support. Topsoil is the nutrient-rich upper layer used for planting. Never use fill dirt where you plan to grow plants, and never use topsoil as structural fill (it decomposes and settles).
How much does fill dirt compact?
Fill dirt typically compacts 10–25% depending on soil type and compaction method. Clay-heavy fill compacts more than sandy fill. When ordering, add 15–20% to your calculated volume to account for compaction and settling. For large projects requiring specific final grades, a geotechnical engineer can provide exact compaction factors for your soil.
How many cubic yards of fill dirt do I need?
Use the calculator above — enter the area length, width, and the depth you need to fill. One cubic yard covers 324 square feet at 1 inch deep, or 108 square feet at 3 inches deep. For large grading projects, fill is often ordered by the truckload — a standard dump truck carries 10–14 cubic yards.
Can I use fill dirt to level a yard?
Yes, but the right approach depends on the grade change needed. For minor leveling (under 4 inches), fill dirt topdressed and graded works well. For significant low spots, you may need to add fill in lifts (4–6 inch layers) and compact each layer before adding more. Never fill over tree root zones — burying roots cuts off oxygen and kills trees over several years.
How much does fill dirt weigh per cubic yard?
Weight varies with moisture and soil type, but fill dirt is commonly in the ~2,000 to 2,700 lb per cubic yard range. If you're ordering by the ton, ask the supplier what density they use for billing.