Dirt Calculator
This dirt calculator works out cubic yards and tons of fill dirt or topsoil, with settling built in. Filling a 20 × 15 ft low spot 6 in deep takes 5.56 cubic yards (150 cubic feet); adding 15% for settling and 5% extra makes 6.71, so order 7 cubic yards, about 6.22–9.05 tons dry.
Example: 20 × 15 ft at 6 in
7 cubic yards
- 6.22–9.05 tons
- 181 cu ft
6.71 yd³ incl. 5% extra + 15% for settling · rounded up to ½ yd
How much dirt do I need?
Dirt is sold by the cubic yard, so start with volume. Multiply the length and width of the area in feet, multiply by the depth of fill in inches ÷ 12 for cubic feet, and divide by 27. If the low spot isn’t the same depth all over, measure the depth at several points across the dip and use the average.
Before it gives you an order, the calculator adds two allowances. Loose fill settles after it’s placed, so fill dirt gets 15% for settling (the compaction section below explains where that figure comes from). Then 5% goes on for spillage and uneven ground, and the total is rounded up to the next half cubic yard.
- Area: 20 ft × 15 ft = 300 sq ft; × 6 in deep = 150 cu ft.
- 150 cu ft ÷ 27 = 5.56 cubic yards.
- Adding 15% for compaction and 5% extra for waste gives 6.71 cubic yards.
- Rounded up to the next 0.5 cubic yard: order 7 cubic yards.
- Weight of fill dirt: 6.22–9.05 tons, depending on moisture and grading.
Settling applies to fill dirt only. With topsoil picked, the same low spot comes to 5.83 cubic yards with the 5% extra, a 6-yard order.
Dirt needed for common jobs
Each cell is the fill dirt order in cubic yards, with settling and spillage included, followed by its dry weight. The 3-inch column fits a shallow regrade, the 6-inch column a low spot and the 12-inch column raising a whole area by a foot.
| Area | 3 in deep | 6 in deep | 12 in deep |
|---|---|---|---|
| 10 × 10 ft, 100 sq ft | 1.5 yd³ , 1–1.5 t | 2.5 yd³ , 2.1–3 t | 4.5 yd³ , 4.1–6 t |
| 20 × 15 ft, 300 sq ft | 3.5 yd³ , 3.1–4.5 t | 7 yd³ , 6.2–9 t | 13.5 yd³ , 12.4–18.1 t |
| 20 × 20 ft, 400 sq ft | 4.5 yd³ , 4.1–6 t | 9 yd³ , 8.3–12.1 t | 18 yd³ , 16.6–24.1 t |
| 30 × 20 ft, 600 sq ft | 7 yd³ , 6.2–9 t | 13.5 yd³ , 12.4–18.1 t | 27 yd³ , 24.9–36.2 t |
| 50 × 30 ft, 1,500 sq ft | 17 yd³ , 15.5–22.6 t | 34 yd³ , 31.1–45.2 t | 67.5 yd³ , 62.2–90.5 t |
Includes 5% extra and 15% for settling, rounded up to the next half cubic yard, as the calculator does. Tons (t) span the sourced density range.
Fill dirt, topsoil or “dirt”: which to order
The calculator offers two kinds of soil. Fill dirt is unscreened subsoil for raising grade and filling holes, such as a stump hole or a sunken corner of the yard. Topsoil is screened soil for lawns and beds. A job that needs both, such as raising a low area and then seeding it, is two orders. Run the calculator once for the fill with its depth and once for the topsoil layer with its own.
The calculator uses the same weights for both. Its sources describe soil by texture and moisture, so fill dirt and topsoil share one dry weight range and one moist range.
Compaction and settling: how much extra to order
Fill dirt settles after it’s placed, and the USDA Natural Resources Conservation Service (NRCS) publishes how much to allow for it. The figures come from two NRCS documents, a conservation standard for dikes and the agency’s handbook on building ponds; they’re the published allowances we found for loose earth fill. NRCS gives each one as a share of the fill’s height, which for a level area is the same share of its volume. For the 20 × 15 ft low spot, each allowance gives a different order:
| How the fill goes in | NRCS settlement allowance | Order with 5% extra |
|---|---|---|
| Compacted in thin layers (rolled) | 5% | 6.13 → 6.5 cubic yards |
| Not rolled | 10% | 6.42 → 6.5 cubic yards |
| Hauled in, dumped and shaped | 15% | 6.71 → 7 cubic yards |
| Dropped in place from an excavator | 20% | 7 → 7 cubic yards |
The calculator uses 15%, the allowance for a delivered load that’s dumped and spread without compaction. For another method, open “How we calculated this” under the result, take the cubic yards before allowances, multiply by 1.05, 1.10 or 1.20 in place of 1.15, then by 1.05 for spillage, and round up to the next half yard.
NRCS applies the allowance to height: the fill goes in that much higher than the finished grade and settles down to it. For the 6-inch low spot at 15%, that means mounding the dirt to about 6.9 inches and letting it settle.
Dirt by the ton: what a yard weighs, dry vs wet
Weight matters even when you order by the yard. Some suppliers sell soil by the ton, and a pickup’s payload is in pounds. What a yard of soil weighs depends on what it’s made of and how much water it holds.
Dry, a cubic yard weighs 1,854–2,697 lb per cubic yard, or 0.93–1.35 tons per cubic yard. That range comes from USDA NRCS bulk densities by soil texture, with clay soils at the light end and sandy soils at the heavy end. South Dakota State University Extension puts an ideal medium-textured soil at 82.9 lb per cubic foot, about 1.12 tons a yard. The calculator’s tons use this dry range.
Moist soil is heavier than the same soil dry. Ottr Landscape Supply, a Boston yard, lists moist screened soil at 2,200–2,400 lb per cubic yard (1.1–1.2 tons per cubic yard). That range sits inside the dry one because the two measure different things: NRCS describes soils in the ground across every texture, while Ottr’s figure is for one product, screened loam, as a supplier sells it. If you’re hauling dirt yourself, plan on the heavy end, as the calculator does when it counts pickup trips.
A ton of dry fill dirt is 0.74–1.08 cubic yards. The table turns one yard and one ton into area at four fill depths.
| Depth | 1 cubic yard covers | 1 ton of fill dirt |
|---|---|---|
| 2 in | 162 sq ft | 120–175 sq ft |
| 4 in | 81 sq ft | 60–87 sq ft |
| 6 in | 54 sq ft | 40–58 sq ft |
| 12 in | 27 sq ft | 20–29 sq ft |
Per-ton coverage spans the sourced density range: heavier material covers less.
Filling holes, trenches and slopes
Holes
A round hole is a cylinder. Pick Circle, enter the diameter across the top, and enter the depth in inches.
- Area: π × (4 ft ÷ 2)² = 12.6 sq ft; × 36 in deep = 37.7 cu ft.
- 37.7 cu ft ÷ 27 = 1.4 cubic yards.
- Adding 15% for compaction and 5% extra for waste gives 1.69 cubic yards.
- Rounded up to the next 0.5 cubic yard: order 2 cubic yards.
- Weight of fill dirt: 1.56–2.27 tons, depending on moisture and grading.
Trenches
Use Rectangle with the trench’s length and width and its depth in inches. Backfilling a 30 ft trench 1 ft wide and 2 ft deep takes 60 cubic feet, or 2.22 cubic yards before allowances; the calculator brings it to a 3-yard order.
Slopes
Ground that slopes evenly from nothing at one edge to a set depth at the other needs a wedge of fill, and a wedge’s volume is its area times its average depth. Raising the low edge of a 20 × 10 ft area by 12 inches, tapering to nothing at the high edge, averages 6 inches: 100 cubic feet, or 3.7 cubic yards, which the calculator turns into a 4.5-yard order.
Backfill around walls, foundations and old pools
Backfill is the same math: the volume of the gap you’re filling. Behind a retaining wall, that’s the wall’s length × the width of the gap × its height. Around a foundation, add one area per side of the house, each with that side’s gap and depth.
Check the wall’s height before you build it. The 2021 International Residential Code (section R404.4) requires an engineered design for a retaining wall that holds back more than 48 inches of unbalanced fill without support at the top, and for a wall over 24 inches tall that resists sideways loads in addition to the soil. Your local code may differ, and the retaining wall cost guide covers the wall itself.
An old in-ground pool is a big box: length × width × average depth. A 16 × 32 ft pool averaging 5 ft deep is 2,560 cubic feet, or 94.8 cubic yards before settling, and 114.5 with the calculator’s allowances. Enter the depth as 60 inches and ignore the calculator’s check on very deep entries. Ask your local building department what it requires before you fill a pool.
How many truckloads?
With soil, a pickup reaches its payload limit with the bed only about half full. Take the 2026 Ram 1500 Tradesman with the 6′4″ box that the calculator uses as its example: it has a bed of 61.5 cubic feet (2.28 cubic yards) and a 2,360 lb payload. That payload carries about 0.88–1.27 cubic yards of dry dirt, or 0.98–1.07 cubic yards at Ottr’s moist weight. The 7-yard low spot works out to 8 pickup trips, or 31 loads in a 6 cu ft wheelbarrow. Your own truck’s payload is on the tire and loading placard on the driver’s side door pillar, where federal rules require it; enter it in the calculator to count your own trips.
Larger orders come by dump truck. The US Army Corps of Engineers’ equipment schedule lists highway dump trucks with 10 to 13 cubic yard bodies on two axles and 16 to 20 cubic yard bodies on three. Those are body sizes; how much soil a supplier puts in one depends on the truck’s weight limit, so ask how many yards they deliver per load. Ottr Landscape Supply, for one, caps soil, gravel, stone and sand at 6 cubic yards a load.
What fill dirt costs
The cost guide for a yard of dirt covers fill dirt and topsoil prices per yard and per ton, dump-truck loads and delivery. If one supplier quotes by weight and another by volume, the cubic yards to tons converter converts one to the other.
Questions people ask
How do you calculate fill dirt needed?
Multiply length × width × depth in feet, then divide by 27 for cubic yards. A 20 × 15 ft low spot filled 6 inches deep is 150 cubic feet, or 5.56 cubic yards. Fill dirt settles after it's placed, so the calculator adds 15% for settling and 5% for spillage. That makes 6.71 cubic yards, rounded up to a 7-yard order.
How much does one ton of fill dirt cover?
A ton of dry fill dirt is 0.74–1.08 cubic yards, depending on the soil. Spread 4 inches deep, that covers about 60–87 sq ft; at 6 inches, about 40–58 sq ft. At the moist-soil weight one Boston supplier publishes, a ton covers about 45–49 sq ft at 6 inches.
How many bags of topsoil make a cubic yard?
36 bags of the 0.75 cu ft size, or 27 one-cubic-foot bags. Go by the cubic feet printed on the bag. A bag labeled only by weight, such as 40 lb, can't be converted to volume reliably, because soil weighs more when it holds more water. A 0.75 cu ft bag spread 2 inches deep covers 4.5 sq ft.
How do I know how much dirt I need to fill a hole?
Treat a round hole as a cylinder: π × (diameter ÷ 2)² × depth, all in feet. A stump hole 4 ft across and 3 ft deep is 37.7 cubic feet, or 1.4 cubic yards. With settling and spillage that's 1.69 cubic yards of fill dirt, so order 2. In the calculator, pick Circle and enter the depth as 36 inches.
How much extra dirt should I order for compaction?
USDA NRCS settlement allowances run from 10% for fill that isn't rolled, through 15% for fill hauled in, dumped and shaped, to 20% for fill dropped from an excavator. Fill compacted in thin layers settles about 5%. The calculator uses 15%, the figure for a delivered load that's dumped and spread without compaction.
How much dirt does it take to fill in a pool?
Multiply the pool's length × width × average depth in feet and divide by 27. A 16 × 32 ft pool averaging 5 ft deep holds 2,560 cubic feet, or 94.8 cubic yards, before settling. With 15% for settling and 5% extra, that's 114.5 cubic yards, a dump-truck job: it would take 131 trips in the calculator's example pickup.
How much does a yard of dirt weigh?
Dry, a cubic yard of soil weighs 1,854–2,697 lb (0.93–1.35 tons), with clay soils at the light end and sandy soils at the heavy end. Ottr Landscape Supply in Boston puts moist screened soil at 2,200–2,400 lb (1.1–1.2 tons) a yard. Water always adds weight, so rain-soaked dirt weighs more again.
Sources
- USDA Natural Resources Conservation Service, Soil Health - Bulk Density (Soil Health Educators Guide sheet). Accessed Oct 19, 2026.
- South Dakota State University Extension (H. Klopp, A. Bly; updated 2023-09-22), Bulk Density is an Indicator of Soil Health. Accessed Oct 19, 2026.
- Ottr Landscape Supply (Boston, MA), Bulk Landscape Material Weight Guide: Dirt, Gravel, Mulch & More. Accessed Oct 19, 2026.
- USDA Natural Resources Conservation Service (Field Office Technical Guide), Conservation Practice Standard: Dike (Code 356), North Dakota, October 2003. Accessed Oct 19, 2026.
- USDA Natural Resources Conservation Service (PDF hosted by Texas A&M AgriLife Soil Testing Lab), Ponds - Planning, Design, Construction (Agriculture Handbook 590). Accessed Oct 19, 2026.
- ScottsMiracle-Gro, Scotts Premium Topsoil - 0.75 CF (product 7113075). Accessed Oct 19, 2026.
- Do it Best (retailer listing), Timberline 1 Cu. Ft. All-Purpose Top Soil (item 701263). Accessed Oct 19, 2026.
- Ram Trucks (Stellantis), 2026 Ram 1500 Specs (Tradesman 4x2 Quad Cab 6'4" box). Accessed Oct 19, 2026.
- The AMES Companies (AMES, Jackson, True Temper, UnionTools brands), Steel Wheelbarrows | Home by AMES. Accessed Oct 19, 2026.
- International Code Council (codes.iccsafe.org), 2021 International Residential Code, Chapter 4 Foundations, Section R404.4 Retaining walls. Accessed Oct 19, 2026.
- U.S. Code of Federal Regulations (NHTSA standard), via Cornell Law School Legal Information Institute, 49 CFR 571.110, FMVSS No. 110 Tire selection and rims ... for motor vehicles with a GVWR of 4,536 kilograms (10,000 pounds) or less. Accessed Oct 19, 2026.
- U.S. Army Corps of Engineers, EP 1110-1-8 Construction Equipment Ownership and Operating Expense Schedule (Vol. 8 Region VIII). Accessed Oct 19, 2026.