Fill Dirt Calculator
Estimate how many cubic yards or tons of fill dirt you need for leveling, grading, and filling holes.
On this page
Settlement, shrink/swell, moisture, and required compaction vary by soil and specification. Use project or supplier values when available.
Grading & Filling Holes
Measure the area and the depth needed to reach the target grade. A 20% compaction allowance is only a planning assumption; actual shrinkage depends on soil and placement.
How to Use the Fill Dirt Calculator
Fill dirt is almost exclusively sold in bulk by the cubic yard. Because it compresses heavily, getting the math right is critical for large grading projects.
- Measure the area: Input the length and width of the area you need to fill or build up.
- Set the depth: Decide how many inches of elevation you need to add.
- Set the allowance and density: Replace the planning defaults with supplier or project values for loose volume and bulk weight.
Fill Dirt Formula
Calculating fill dirt uses the finished geometric volume, an editable loose-volume allowance, and an editable density for weight.
Step 1: Calculate Cubic Feet
Volume (ft³) = Length (ft) × Width (ft) × (Depth in inches ÷ 12)
Step 2: Apply Loose-Volume Allowance
Order Volume = Finished Volume × (1 + Selected Allowance %)
Step 3: Convert to Yards and Tons
Cubic Yards = Order Volume ÷ 27
US Tons = (Order Volume × Selected Density) ÷ 2,000
Fill Dirt Example
You need to raise the elevation of a 20-foot by 20-foot section of your yard by 6 inches.
- Area: 20 × 20 = 400 square feet.
- Volume: 400 × (6/12) = 200 cubic feet.
- Add Compaction: 200 × 1.2 = 240 cubic feet.
- Convert to Yards: 240 ÷ 27 = 8.88 cubic yards.
- Related material: If you need other materials for this project, check out our Topsoil Calculator.
Conclusion: The calculated quantity is about 9 cubic yards before confirming settlement, compaction, and supplier delivery increments.
Tips for Using Fill Dirt
- Don't plant in it: Fill dirt is meant for structure, not farming. If you are trying to plant a lawn over a built-up area, fill the area with fill dirt up to the final 4 inches, and then use quality topsoil for the top 4 inches.
- Check for clean fill: Always ensure you are buying "Clean Fill." This means the dirt has been inspected and is certified free from environmental toxins, large chunks of concrete, asphalt, and organic debris that will rot and sink over time.
- Grade away from your house: If you are using fill dirt near a foundation, always grade the dirt so it slopes down and away from the house (at least 1 inch of drop for every 1 foot of distance) to prevent water damage to your basement.
Transparent estimate
Accuracy, assumptions, and sources
Reviewed September 29, 2026
Calculates placed volume with editable loose-volume and bulk-density planning assumptions.
What this estimate assumes
- The default allowance adds 20% loose material.
- Default bulk density is 74 lb/ft³, close to one short ton per cubic yard.
What it cannot know
- Actual shrink/swell depends on soil classification, moisture, lift thickness, and compaction specification.
Reference links
- NIST Guide for SI unit conversion
- Use the product label or a current supplier quote for coverage, density, and pack size
Found a questionable result? Report the inputs and result so the calculation can be rechecked.
Frequently Asked Questions
What is the difference between fill dirt and topsoil?
Fill dirt is subsoil taken from deep beneath the earth's surface. It lacks organic matter, meaning plants cannot grow in it, but it is highly stable and packs tightly. Topsoil is the nutrient-rich upper layer used specifically for growing plants and grass.
How much does a cubic yard of fill dirt weigh?
Weight varies with soil classification, moisture, debris, and compaction. The calculator starts at 74 lb/ft³, close to one US ton per cubic yard, but the supplier or geotechnical specification should control when payload matters.
Why is there a loose-volume allowance?
Delivered loose soil can shrink after placement and compaction, while some excavated soils swell. Twenty percent is only a planning default. Use a project-specific shrink/swell or compaction factor when one is available.
How deep can I pour fill dirt at once?
When filling deep holes or building up foundations, you should pour fill dirt in 'lifts' (layers) of 4 to 6 inches, compacting each layer with a plate compactor or hand tamper before adding the next. This prevents future settling.