Tons per cubic yard equals the density in pounds per cubic foot times 0.0135. That is the whole conversion. The hard part is the density, which is a property of the material and of how tightly it is packed — dense-graded crushed base compacted in place runs about 1.83 tons per cubic yard, concrete 1.96, water 0.84.
The formula, both ways
A cubic yard is 27 cubic feet and a short ton is 2,000 pounds. Everything else follows:
cubic yards = tons × 2,000 ÷ (density (lb/ft³) × 27)
Shortcut: tons per cubic yard = density (lb/ft³) × 0.0135, and density = tons per cubic yard × 74.07.
So a material at 135 lb per cubic foot is 1.82 tons per cubic yard, and a material at 100 lb per cubic foot is 1.35. Nothing about the arithmetic is difficult. The trouble starts when somebody hands you a single factor — 1.4, or 1.5, or "a yard and a half" — and applies it to whatever is in the truck.
Measured factors, by material
Conversion factors for aggregate are surprisingly hard to source. A 2023 research report prepared for the Wisconsin Department of Transportation surveyed state DOTs and found that only about 23% of them — six out of twenty-six — publish conversion factors at all. The same study then went and measured them, on Wisconsin materials, in the compacted and the loose state. Those measurements are the best public numbers available for construction aggregate.
| Material | Tons per compacted yd³ | lb/ft³ | Expansion to loose |
|---|---|---|---|
| Crushed stone base, ¾ in | 1.80–1.86 | 133–138 | 36–47% |
| Crushed stone base, 1¼ in | 1.79–1.98 | 133–147 | 34–52% |
| Crushed stone base, 3 in | 1.78–1.87 | 132–139 | 34–45% |
| Breaker run | 1.82–1.87 | 135–139 | 27–30% |
| Select crushed material | 1.77–1.81 | 131–134 | 27–29% |
| Granular backfill, Grade 1 or 2 | 1.62–1.66 | 120–123 | 38–52% |
| Structure backfill, Grade A or B | 1.50–1.72 | 111–127 | 35–48% |
| RAP base (asphalt millings) | 1.64–1.71 | 121–127 | 35–46% |
| RCA base (recycled concrete) | 1.65–1.75 | 122–130 | 37–60% |
WisDOT's own statewide guideline for dense-graded base is 1.75 to 2.10 tons per cubic yard, so the measured values sit comfortably inside it. For materials that are not aggregate, the numbers come from federal design practice: reinforced concrete 150 lb per cubic foot, compacted soil 120 and fresh water 62.4, all from FHWA's public LRFD design example citing AASHTO's dead-load table, and 140 to 150 lb per cubic foot for normalweight concrete from NRMCA.
| Material | lb/ft³ | Tons per yd³ |
|---|---|---|
| Concrete, normalweight | 145 (range 140–150) | 1.96 |
| Concrete, reinforced | 150 | 2.03 |
| Compacted earth fill | 120 | 1.62 |
| Fresh water | 62.4 | 0.84 |
Loose or compacted: the mistake that puts a job a third short
This is the part most conversion charts leave out, and it is worth more than the rest of the page. Compaction changes the volume. It does not change the weight.
Work an example through. You need 10 cubic yards of ¾ inch crushed base in the ground, compacted:
- Tons: 10 compacted cubic yards × 1.83 = about 18.3 tons. This number does not move.
- Loose cubic yards on the trucks: 10 × (1 + 36% to 47%) = 13.6 to 14.7 loose cubic yards.
- If you order 10 yards: you get about 13 tons of stone and finish roughly a third short of the depth you specified.
The expansion is not the same for every material either. Breaker run and select crushed sit at 27% to 30%, because coarse angular rock does not tighten up much. Recycled concrete aggregate runs 37% to 60% — the widest spread in the study, which makes the loose yardage on an RCA job the least predictable figure on the page.
The gravel calculator handles both ends of this: enter the compacted depth you want in the ground and it returns the tons to order and the loose cubic yards that will arrive, with the published range on each. For a straight conversion in either direction, the cubic yards to tons converter shows the density it used and where the figure comes from.
Why sand, topsoil and mulch are not on this page
Every other conversion chart on the internet has a line for topsoil. This one does not, and the reason is that nobody publishes a defensible number.
FHWA's own soils manual gives the range for a clean fine-to-coarse sand as 85 to 138 lb per cubic foot — and that is the same sand, moved from its loosest packing to its densest, before you add a drop of water. In tons per cubic yard that is 1.15 to 1.86. A chart that says "sand: 1.35" is picking a point in the middle of a factor-of-two spread and presenting it as a fact.
Screened topsoil, mulch, compost and decorative stone are worse, because moisture and organic content move them further still. The honest answer for all of them is the same: get the number from the material you are actually buying.
Getting your own number off a delivery ticket
This takes ten seconds and beats every published table, because it is your material from your supplier.
18.5 tons against 10 yards → 18.5 × 2,000 ÷ 270 = 137 lb/ft³, or 1.85 tons per cubic yard.
Write it on the inside of the job folder. Two things to keep straight when you do: the yards on the ticket are almost always loose yards, so the density you get is a loose density and belongs with loose volumes; and a ticket taken after a rainy week carries water you paid for and will not have next month.
Asphalt is the one material where the right number is always available and never typical. Hot mix density is the bulk specific gravity of the mix design, Gmb, printed on the mix design sheet for the job. Multiply Gmb by 62.4 for pounds per cubic foot, or by 0.8424 for tons per cubic yard. There is more on that method, and on why the "145 lb per cubic foot" every calculator hard-codes is not a number anyone should rely on, in our piece on asphalt density.
Three different tons
- Short ton — 2,000 lb. The ton on an American scale ticket, and the one every figure on this page uses.
- Metric tonne — 1,000 kg, or 2,204.6 lb. About 10% heavier than a short ton. Common on imported equipment plates and in specifications written abroad.
- Long ton — 2,240 lb. Rare on land, still seen in marine and some legacy contexts.
A 12% error between a short ton and a long ton is exactly the size of mistake that survives a review, because the number still looks about right. If a document does not say which ton it means, find out before you price anything from it.
Bottom line
- Tons per cubic yard = lb/ft³ × 0.0135. The formula is trivial; the density is the work.
- Dense-graded crushed base measured compacted in place: 1.80 to 1.98 tons per cubic yard, depending on the size.
- The same rock loose in a truck is a third to a half more volume for the same weight. Ask which yard you are being quoted.
- Order by the ton when you can. A ton is the same number everywhere in the transaction.
- No published factor beats one worked out from your own delivery ticket.