Introduction
Fill dirt is the soil used to raise low spots, build pads, fill holes, and level ground. Buying too little stalls your job. Buying too much wastes money. This fill dirt calculator tells you how much dirt to order before the first truck rolls in.
Enter your area as a rectangle, circle, triangle, acreage, or plain square footage. Add your fill depth in inches, feet, centimeters, or meters. Pick your soil type, and you get cubic yards, tons, pounds, and the number of truckloads you need.
Dirt settles once it is placed and packed down. That is why the calculator adds a compaction buffer, set at 15% by default. You can change that buffer, add a waste percent for spillage during hauling and spreading, and see the math laid out step by step.
You can also type your job in plain words, sketch the area on a scaled grid, add prices to get a cost estimate, and stack several zones into one grand total. Results copy and print in one click, so you can hand them straight to your supplier.
How to Use Our Fill Dirt Calculator
Enter the size of your area, how deep the fill will be, and the type of dirt. You get cubic yards to order, the weight in tons, how many truckloads you need, and the cost if you add a price.
Unit System: Pick Imperial for feet and tons, or Metric for meters and tonnes. All fields switch over for you.
Describe your project in plain language: Type or speak something like "300 by 80 feet, 8 inches of fill, clay soil," then press the wand button to fill the fields.
Project Type: Tap a job type like Building Pad, Parking Lot, or Utility Trench. This sets a normal depth, waste, and compaction. You can still change any number.
Area Shape Mode: Choose Rectangle, Circle, Triangle, Acreage, or Square Footage to match your site.
Length and Width: For a rectangle, type the two sides of your area and pick feet or meters.
Diameter: For a circle, type the distance straight across the middle.
Base and Height: For a triangle, type the bottom edge and the height straight up from it.
Acreage: Type the land size in acres or hectares if you already know it.
Area (direct entry): Type the square feet or square meters if you already have the area.
Calculation Mode: Choose Flat Fill for even depth. Choose Slope / Wedge Fill when the dirt tapers from zero at one edge to full depth at the other.
Quick-Fill Dimension Presets: Tap Small Yard, Backyard, or Foundation to load common sizes fast.
Draw Area on Map: Open this to sketch odd shapes. Set what one grid square equals, drag a box or tap corners, then press Use This Area to send it to the calculator.
Fill Depth: Type how deep the dirt will go and pick inches, feet, centimeters, or meters. Use the plus and minus buttons to nudge it.
Soil / Fill Type: Pick mixed, sandy, loam, silty, or clay fill. This sets the weight per cubic yard.
Compaction Buffer: Leave this on to order extra dirt for settling. Move the slider or tap a soil shortcut to set the percent.
Waste / Overage %: Under Advanced Options, add extra for dirt lost during hauling and spreading.
Compaction %: Type an exact buffer percent here if you don't want to use the slider.
Truck Type: Choose your dump truck size so the calculator can count loads.
Price per Ton and Price per Cubic Yard: Add your supplier's price to see the total material cost. Leave blank to skip.
Calculate and Reset: Press Calculate to see results and the step-by-step math. Press Reset to start over.
Add Zone: Save the current result and add another area. The table adds up all zones for one grand total.
What Is Fill Dirt?
Fill dirt is plain subsoil dug from below the topsoil layer. It has little or no organic matter, so it does not rot, shrink, or sink much over time.3 That makes it the right material to raise low spots, build up a pad, fill a hole, or level a yard before you pour concrete or lay sod.
Fill Dirt vs. Topsoil
Topsoil is dark, rich, and full of roots and organic material. It is great for growing grass and plants, but it settles and breaks down, so it is a poor base for building. Federal highway specifications require the topsoil to be removed before fill is built up over natural ground.3 Fill dirt is the opposite. Use fill dirt for the bulk of the work, then add a few inches of topsoil on top if you plan to plant.
Common Uses for Fill Dirt
- Building pads: a firm, level base under a house, shed, or slab
- Parking lots and road base: raises grade before gravel or asphalt
- Trench backfill: refills the ditch after pipe or cable goes in
- Foundation backfill: packs soil back against basement or footing walls
- Grading and drainage: slopes the ground so water runs away from buildings
- Filling holes: old pools, stump holes, and washouts
How Fill Dirt Is Measured and Sold
Fill dirt is sold by the cubic yard or by the ton. One cubic yard equals 27 cubic feet, the space inside a cube 3 feet on every side.1 Weight depends on the soil type and how wet it is. In the ground, dry loam or silt weighs about 2,180 to 2,980 pounds per cubic yard, and wet loam or silt about 3,500 to 4,000 pounds.2 Most fill dirt runs about 1.4 to 1.8 tons per cubic yard. Whether sand or clay is heavier depends on the water in it: dry, loose sand weighs about 2,600 to 2,900 pounds per cubic yard and dry, loose clay about 1,700 to 2,000, but wet clay in the ground weighs 3,360 to 4,200 pounds.2
Why You Should Order Extra
Loose dirt takes up more room in the truck than it does after it is packed down.2 When you spread it and run a compactor or roller over it, the volume drops. That is called compaction or settling. How much extra you need depends on the soil. One cubic yard of compacted fill takes about 1.17 cubic yards of loose sand or gravel, 1.39 of loose loam or 1.59 of loose clay, so order about 17%, 39% or 59% more than the finished volume.2 These are average figures.2 Add a little more, often 5% to 15%, for waste lost during hauling and spreading. Running short means paying for a second delivery, which costs far more than a few extra yards up front.
Truckloads and Delivery
Dirt is delivered by dump truck, and bigger trucks carry more per load. Ask your hauler for the bed volume and legal payload of its trucks. Trucks are also limited by weight, so a load of wet clay may fill less space than a load of dry sand. Always round truckloads up, since you cannot buy half a load.
Tips for a Good Fill Job
- Strip grass, roots, and soft mud before you place fill.3
- Place dirt in layers, or "lifts," about 6 to 8 inches thick, and compact each one.
- Dirt that is slightly damp packs the best. Too dry will not bind; too wet turns to mush.
- Slope the finished grade away from buildings so water drains off. For a house, the International Residential Code calls for the ground to fall at least 6 inches within the first 10 feet from the foundation walls.4
- Check local rules. Many towns need a permit before you haul in large amounts of fill or change drainage.
- Call 811 or your local utility locate service before you dig.6