Fill Dirt Calculator
Calculate exactly how many cubic yards or tons of fill dirt you need for leveling, grading, and filling holes.
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Grading & Filling Holes
When bringing the ground level up to a target grade, fill dirt is required. Always account for 20% volume shrinkage as the dirt compacts.
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.
- Leave compaction checked: Unless you want your dirt to settle lower than your target height after the first rainstorm, always include the 20% compaction factor.
Fill Dirt Formula
Calculating fill dirt requires a standard volume equation with a compaction multiplier applied at the end.
Step 1: Calculate Cubic Feet
Volume (ft³) = Length (ft) × Width (ft) × (Depth in inches ÷ 12)
Step 2: Apply Compaction
Compacted Volume = Volume (ft³) × 1.20
Step 3: Convert to Yards
Cubic Yards = Compacted Volume ÷ 27
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.
Conclusion: You should order exactly 9 cubic yards of fill dirt.
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.
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?
One cubic yard of dry fill dirt weighs approximately 2,000 lbs (1 ton). If the dirt is wet or has a high clay content, it can weigh up to 2,700 lbs (1.35 tons) per yard.
Why do I need to add 20% for compaction?
When fill dirt is delivered, it is loose and full of air. As you spread it out and compact it (or as it naturally settles over time via rain), it shrinks in volume by about 20%. If you don't account for this, your graded area will sink below your target level.
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.