Dirt Calculator

How to calculate how much dirt you need

Dirt is sold by the cubic yard. Work out the volume the finished fill will take up, then add an allowance for settling, because loose dirt off a truck packs down once it is spread, walked on and rained on.

Divide the depth by 12 when you measure it in inches, and divide by 27 because a cubic yard is 3 × 3 × 3 = 27 cubic feet. The 1.15 is our settling allowance, explained below.

Example: raising a low corner of the yard

An area 20 ft × 30 ft that needs to come up 6 inches, filled with ordinary fill dirt:

1. Area: 20 × 30 = 600 sq ft
2. Finished volume: 600 × 6 ÷ 12 = 300 cu ft = 11.11 cu yd
3. With settling: 11.11 × 1.15 = 12.78 cu yd to order
4. Weight: 12.78 × 1.00–1.20 tons = 12.8–15.3 tons
5. Trucks: 2 tandem dump truck loads at 12 cu yd, or 3 single-axle loads at 6 cu yd. In a pickup carrying 2,000 lb of cargo it would be 16 trips.

Example: hauling away dirt you dig out

Dirt swells when you dig it, so the pile is bigger than the hole. Digging out a 12 × 16 ft patio area 8 inches deep:

1. Volume in the ground: 12 × 16 × 8 ÷ 12 = 128 cu ft = 4.74 cu yd
2. Loose, after digging: 4.74 × 1.28–1.50 = 6.07–7.11 cu yd (swell factors in the table below)
3. Weight does not change when it swells: 4.74 cu yd × 3,026–3,371 lb per cu yd in the ground = 7.2–8.0 tons
4. That is 2 single-axle loads, 1 tandem load, or about 8 pickup trips.

The calculator above works the other way, from a finished depth to an order. For digging, use this example’s steps.

How much a yard of dirt weighs

A cubic yard of the same dirt weighs different amounts in the ground (called bank), loose in a pile or truck, and compacted: FHWA lists topsoil at 2,427, 1,618 and 3,278 lb. Weights below are from the FHWA tables reproduced in a 2023 Wisconsin DOT research report, converted from kg/m³.^[1]

Delivered dirt is loose, so the calculator uses loose weights. The source table prints damp clay lighter than dry clay, which is odd; we show it as printed. For comparison, undisturbed mineral soil weighs 1,686–2,360 lb per cubic yard when dry.^[2] Moist dirt weighs more, so ask your supplier what their yard of fill weighs.

Settling: why the calculator orders 15% more

We could not find a published standard for how much spread fill or topsoil settles. Here is what the sources do say:

• Penn State measures lawn topsoil as a “firmed or settled” depth, so the loose layer has to start deeper than the target.^[3]
• Rutgers notes that mineral soils keep their volume after the initial settling, while organic mixes keep shrinking.^[4]
• Oregon State warns that soil with more than 15% organic matter by volume settles considerably as the organic matter breaks down.^[5]
• Miracle-Gro says two 1.5 cu ft bags fill a 2 × 2 ft bed 6 inches deep. That bed holds 2 cu ft, so the maker allows 1.5 times the volume.^[6]
• At the far end, packing loose topsoil back to its in-ground weight takes 2,427 ÷ 1,618 = 1.50 yards of loose soil per finished yard (FHWA figures).^[1]

Dirt that is raked, rolled and watered does not get close to its in-ground density, so we use 1.15 (15% extra) as our estimate for fill that is spread and firmed but not machine-compacted. It is a starting point, not a measured value. Clay and fill dirt use the same factor.

Bank, loose and compacted: swell and shrink factors

Earthmoving tables give two factors: how much dirt swells when dug (bank to loose) and how much it shrinks when compacted in a fill (bank to compacted). The last column is our calculation from the first two.^[1]

The FHWA table prints 56% for topsoil swell, but its own weights (2,427 in the ground, 1,618 loose) work out to 50%. The report notes that these factors vary by about ±33%, and Burch’s shrink values are for compaction to 100% of the Standard Proctor density.

Field results spread widely. In Wisconsin’s tests, the volume of compacted clays differed from their in-ground volume by only −5% to +9%. Florida DOT recommends a 15–20% shrinkage factor for embankment, and Tennessee DOT uses 30–50% for light cuts and fills of 1–2 ft.^[1]

If you will compact the fill

For fill compacted in layers with a plate compactor or roller, the dirt and clay rows above point to about 1.4–1.7 loose yards per finished yard, well above our 1.15. To cover that, raise Extra for waste to about 22–48% and confirm with your supplier.

Trips: a pickup runs out of payload first

A standard 8 ft pickup bed holds about 2 cubic yards filled level (2.22 for a 5 × 8 ft bed; one Texas producer says 2.5).^[7][8][9] Dirt is too heavy for that. Two cubic yards of fill at 2,000–2,400 lb each weigh 4,000–4,800 lb. Ford lists 2,440 lb as the most a 2026 F-150 can carry, and only in the configuration built for maximum payload; payload also includes the people in the cab, and most half-ton pickups are rated lower.^[10]

The calculator assumes 2,000 lb of cargo per trip, after the people in the cab, which is 0.83 cu yd of fill dirt at the heavy end of the range. Your truck’s real payload is on the label inside the driver’s door; overloading affects braking and steering.

Dump trucks are counted by volume: a single-axle truck carries about 6 cu yd and a tandem-axle truck usually 12 or 14 cu yd, per Texas DOT.^[11] Heavy wet soil can reach the legal weight limit before the bed is full, so ask the supplier how many yards they can bring per load.

Related calculators

• Topsoil calculatorLawns and beds, bulk or bagged
• Cubic yard calculatorAny shape to cubic yards
• Gravel calculatorDriveways, paths and bases in tons and yards
• Project materials listPrint everything you added from each calculator

Prepared by the Yard & Build editors. The formulas behind this calculator are checked against hand-worked answers every time the site is built. Soil values checked September 26, 2026.