Gravel Calculator
Enter the area and the depth of stone you want in the ground, pick the material, and get the tons to order, the loose cubic yards that will arrive on the truck and the compacted volume in place. Order by the ton when you can: the ton is the same number at the quarry, on the scale ticket and in the trench.
Order this much stone
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Results are estimates for planning purposes. Verify with your supplier, engineer, or a qualified professional before ordering material or performing work.
Coverage per ton, by depth
| Depth in place | ft² per ton | Tons per 100 ft² | Compacted yd³ per 100 ft² |
|---|---|---|---|
| 2 in | 89 | 1.13 | 0.62 |
| 3 in | 59 | 1.69 | 0.93 |
| 4 in | 44 | 2.26 | 1.23 |
| 6 in | 30 | 3.39 | 1.85 |
| 8 in | 22 | 4.52 | 2.47 |
| 12 in | 15 | 6.78 | 3.70 |
For ¾ in dense-graded crushed base at 1.83 tons per compacted cubic yard, the value the WisDOT study measured. Heavier or lighter material scales the tons in proportion; the cubic yards do not change. Halve the depth and you double the coverage.
The yard in the truck is not the yard in the trench
This is the mistake that puts a job a third short. Compaction changes the volume and leaves the weight alone. The same WisDOT study measured how much each material expands going from compacted in place to a loose stockpile:
| Material | Tons per compacted yd³ | Compacted → loose |
|---|---|---|
| Crushed stone base, ¾ in | 1.80–1.86 | 36–47% |
| Crushed stone base, 1¼ in | 1.79–1.98 | 34–52% |
| Crushed stone base, 3 in | 1.78–1.87 | 34–45% |
| Breaker run | 1.82–1.87 | 27–30% |
| Select crushed material | 1.77–1.81 | 27–29% |
| Granular backfill, Grade 1 or 2 | 1.62–1.66 | 38–52% |
| Structure backfill, Grade A or B | 1.50–1.72 | 35–48% |
| RAP base (asphalt millings) | 1.64–1.71 | 35–46% |
| RCA base (recycled concrete) | 1.65–1.75 | 37–60% |
Measured values from WHRP G22-05 (WisDOT, December 2023), Table 4.11. WisDOT's own statewide guideline for dense-graded base is 1.75 to 2.10 tons per cubic yard. The study also found that only about 23% of the state DOTs it surveyed publish conversion factors at all — which is why so few of these numbers are findable anywhere.
Ordering notes
- Order by the ton. A ton is the same number at the quarry, on the scale ticket and in the trench. A yard is three different numbers.
- Get your own density in ten seconds. Tons billed × 2,000 ÷ (cubic yards ordered × 27) is the lb/ft³ of that material from that supplier. Enter it in the custom field and everything after that is exact rather than typical.
- No pea gravel, river rock or decomposed granite here. Nobody publishes a defensible figure. FHWA's own soils manual spans 85 to 138 lb/ft³ for a clean sand on packing alone — a midpoint would be wrong half the time. Use the custom field with your supplier's number.
- Depth is a design decision. This page converts a depth into a quantity; it does not choose one. Traffic, subgrade and, on public work, the specification set the thickness.
- Think about where the pile goes. If the stone is being stockpiled next to an open excavation, 29 CFR 1926.651(j)(2) keeps spoil and materials at least 2 ft back from the edge, or retained. A delivered load of base is a surcharge load on the trench wall.
How it's calculated
- Area
rectangle: A = length × width · circle: A = π / 4 × diameter² · triangle: A = base × height / 2- Compacted volume in place
V (ft³) = A (ft²) × depth (in) / 12 → yd³ = ft³ / 27- Volume to buy
V order = V × (1 + extra % / 100)- Tons
tons = V order (compacted yd³) × conversion factor (tons per compacted yd³)The WisDOT conversion factors are compacted unit weights expressed in short tons per cubic yard. Measured values: dense-graded base 1.80–1.86 (¾ in), 1.79–1.98 (1¼ in), 1.78–1.87 (3 in); breaker run 1.82–1.87; select crushed 1.77–1.81; granular backfill 1.62–1.66; structure backfill 1.50–1.72; RAP base 1.64–1.71; RCA base 1.65–1.75. WisDOT's own statewide guideline range for dense-graded base is 1.75 to 2.10.- Loose cubic yards on the truck
loose yd³ = V order (compacted yd³) × (1 + expansion %)Measured compacted-to-loose expansion: 36–47% for ¾ in base, 34–52% for 1¼ in, 34–45% for 3 in, 27–30% breaker run, 27–29% select crushed, 38–52% granular backfill, 35–48% structure backfill, 35–46% RAP, 37–60% RCA. Compaction changes the volume, never the weight — which is why the ton is the safer unit to order in.- Coverage per ton
ft² per ton = 2,000 / (density (lb/ft³) × depth (in) / 12)At 4 in of ¾ in crushed base, one ton covers about 44 ft². At 2 in it covers about 89 ft²; at 6 in, about 30 ft².
Frequently asked questions
200 square feet at 4 inches is 66.7 cubic feet, or 2.47 cubic yards in the ground. With a 5% allowance that is 2.59 compacted cubic yards, which is about 4.7 tons of ¾ inch crushed base — or roughly 3.7 loose cubic yards if your supplier sells by the yard.
About 44 square feet at 4 inches deep, using the 1.83 tons per cubic yard the WisDOT study measured for ¾ inch dense-graded base. At 2 inches a ton covers about 89 square feet, at 3 inches about 59, and at 6 inches about 30. Halve the depth and you double the coverage.
By the ton whenever you have the choice. Compaction changes the volume but not the weight, so a yard means something different at the quarry, in the truck and in the trench — the study behind this page measured aggregates expanding 27% to 60% between the compacted state and a loose stockpile. A ton is a ton in all three places, and it is what the scale ticket says.
Because loose stone has more air in it. To finish with 10 compacted cubic yards of ¾ inch base in the ground you need roughly 14 loose cubic yards on the trucks, still the same 18 or 19 tons. If you order 10 loose yards for a 10 yard hole, you come up short by about a third.
Because no primary source publishes a usable density for them. FHWA's own soils manual puts a clean sand anywhere between 85 and 138 lb per cubic foot on packing alone, and decorative stone varies with the rock, the roundness and the moisture. A midpoint would look authoritative and be wrong half the time. Get the figure from your supplier's ticket — tons billed × 2,000 ÷ (yards ordered × 27) gives you lb/ft³ — and enter it in the custom field.
That is a design question, not an arithmetic one. Depth depends on the traffic, the subgrade and, on anything public, the specification you are building to. This calculator converts the depth you were given into a quantity; it does not choose the depth. If nobody has given you one, ask the supplier what the local practice is for the traffic you expect.
Yes, and that is the point of it. Enter the depth you want in the ground, compacted. The tons come from the compacted unit weight, and the loose cubic yards that will arrive are the compacted volume multiplied by the measured expansion factor for that material. Both figures and their published ranges are shown with the result.
RAP is reclaimed asphalt pavement — milled asphalt reused as a base course. RCA is recycled concrete aggregate, crushed concrete used the same way. Both were measured in the WisDOT study: 1.64 to 1.71 tons per compacted cubic yard for 1¼ inch RAP base and 1.65 to 1.75 for RCA. RCA also has the widest expansion range of any material tested, 37% to 60%, so the loose yardage on a recycled concrete job is the least predictable number on the page.
Sources & references
- WHRP G22-05 — Weight-Volume Relationships and Conversion Factors for Soils and Aggregates of Wisconsin (WisDOT, December 2023): Table 4.11 measured conversion and expansion factors, Table 1.2 WisDOT statewide values, Table 4.8 loose and compacted unit weights
- FHWA NHI-06-088 — Soils and Foundations Reference Manual, Volume I, Table 5-4: the dry unit weight of a clean fine-to-coarse sand runs from 85 to 138 lb/ft³ on packing alone — why no single figure is offered for sand or decorative stone
- 29 CFR 1926.651(j)(2) — spoil, materials and equipment kept at least 2 ft back from the edge of an excavation, or retained: where the stockpile goes matters as much as how much of it there is
Content checked against these sources — last reviewed August 28, 2026.