How Many Yards in a Ton? The Reasoning That Produces the Number

There is no single answer, because a ton measures weight and a cubic yard measures volume. Bulk density is the only bridge between them, and the arithmetic is one line: cubic yards per short ton = 2,000 ÷ (pounds per cubic foot × 27). At a loose density of 105 lb/ft³, one short ton of crushed stone occupies 0.71 cubic yards. Screened topsoil at 81 lb/ft³ gives 0.91 yards per ton. Bark mulch at 15 to 30 lb/ft³ gives 2.5 to 4.9 yards per ton. Only your supplier's measured density converts your own order correctly.

A ton is weight, a yard is volume, and the supplier picks which one to quote

NIST Handbook 44, Appendix C, fixes the units. An unmodified "ton" in United States trade means the 2,000-pound short ton, with "tn" required as the device abbreviation since January 1, 2014, and a cubic yard is 27 cubic feet. Neither unit tells you anything about the other until you know what one cubic foot of the material weighs.

Which unit you get quoted in is partly a legal question. NIST Handbook 130, the model regulation states adopt for methods of sale, says at Section 2.29(a) that top soil, fill dirt, aggregate or chipped rock, sand, decomposed granite, landscape rock and cinders "must be sold by the cubic meter or cubic yard or by weight." Either is lawful. Section 2.18.2 grants mulch no latitude: all mulch must be sold "in terms of the cubic yard or cubic foot." The stone yard may bill you in tons; the mulch yard may not.

| Material | Loose density (lb/ft³) | Pounds per loose yd³ | Loose yd³ per short ton | Typically sold by | |---|---|---|---|---| | Crushed stone, ¾ in (#57) | 95–105 | 2,565–2,835 | 0.71–0.78 | weight or volume | | Crusher run / dense-graded base | 105–115 | 2,835–3,105 | 0.64–0.71 | weight | | Washed concrete sand | 100–110 | 2,700–2,970 | 0.67–0.74 | weight or volume | | Screened topsoil | 75–90 | 2,025–2,430 | 0.82–0.99 | volume or weight | | Unscreened fill dirt | 90–110 | 2,430–2,970 | 0.67–0.82 | weight or volume | | Bark mulch | 15–30 | 405–810 | 2.5–4.9 | volume only |

Those ranges come from supplier spec sheets and agree with the physics: limestone at bulk specific gravity 2.65 with 40 to 45 percent voids lands between 91 and 99 lb/ft³ loose. Your quarry's number replaces the column.

Fix four things before you convert anything

Material and gradation. Number 57 stone and crusher run from the same pit differ by roughly 10 lb/ft³, because one is open-graded and the other carries fines that fill its voids.

Unit system. A short ton is 2,000 pounds, a metric tonne 2,204.6, a long ton 2,240. Handbook 44 notes the long ton sees United States commercial use "to only a very limited extent." A calculator quietly running on tonnes overstates volume per ton by 10.2 percent.

Loose, bank, or compacted. Three volumes for one mass. Suppliers haul and weigh loose; you install compacted.

Dry basis or as delivered. ASTM C29/C29M and its AASHTO twin T 19, the tests behind published bulk densities, measure on a dry basis. The standard states outright that the relationship between compaction in the test measure and in a hauling unit or stockpile is unknown, and that stockpiled aggregate carries absorbed and surface moisture. The scale under the truck weighs that water.

Each of those four settings multiplies the final figure, which is why a single calculator output tells you so little. I draw signal chains for a two-microphone rig in a pantry for that same reason: preamp gain, converter headroom and plugin makeup each operate on the level, and a chain showing only its last value will lie about where the trouble started. Quarry density, stockpile moisture, spread loss and compaction do precisely that to a gravel order.

What to ask the supplier for, and the standard behind each answer

1. Bulk density, by ASTM C29/C29M or AASHTO T 19, with the condition stated. Rodded density runs several percent above loose for the same stone.
2. Moisture. Total evaporable moisture comes from ASTM C566 (AASHTO T 255); absorption from ASTM C127 for coarse aggregate or C128 for fine. Free moisture is the first minus the second, and free moisture is what the scale charges you for. The National Precast Concrete Association, citing ACI 304R, reports free moisture in fine aggregate holding stably at 6 percent and occasionally 8. On a 20-ton sand delivery, 6 percent is about 2,260 pounds of water. Wind and rain worked that stockpile all night, and nobody dried it before the loader arrived.
3. Maximum dry density and the test method, for anything compacted. AASHTO T 180 applies 56,000 ft-lbf/ft³ against T 99's 12,400, so the two return different maximums for identical material.
4. The scale ticket: gross, tare, net, and the scale's certification. It carries the only figure on the job that somebody measured on your material.

Loose cubic yards versus compacted cubic yards

This comparison decides the order, and calculators skip it. A 20-by-60-foot driveway is 1,200 ft². At a 4-inch finished depth, that is 400 ft³, or 14.8 compacted cubic yards.

Now convert to weight. Wisconsin DOT's Standard Specification 301.3.4.3 requires each layer compacted to "95 percent of maximum density, or more," with maximum density determined by WTM T99 method C or D and in-place density by AASHTO T191. Take a dense-graded base with a Proctor maximum of 138 lb/ft³. Ninety-five percent is 131 lb/ft³ in place, dry. Multiply: 400 ft³ × 131 = 52,400 pounds, or 26.2 short tons dry. Per compacted yard that is (131 × 27) ÷ 2,000 = 1.77 tons.

The ticket reads higher, because the truck carries water. At 4 percent free moisture, 26.2 dry tons arrives as 27.3 tons, and at 110 lb/ft³ loose those tons occupy 54,540 ÷ 2,970 = 18.4 loose cubic yards.

One job, three correct answers: 14.8 compacted yards, 18.4 loose yards, 27.3 tons. The loose-to-compacted ratio is 1.24, and every rule of thumb telling you to add 25 percent for a crusher-run base is describing it. Open-graded stone such as #57 barely densifies and gets no such allowance.

Four assumptions that make a calculator's answer wrong

A single default density for "gravel" is the first. An error of 15 lb/ft³ across 400 ft³ is 6,000 pounds, a full 3 tons on a small driveway. Second, dry-basis density applied to a wet delivery: the 4 percent moisture above is 1.1 tons of water you paid for and cannot spread. Third, a compacted volume treated as loose, which is the 1.24 factor going missing. Fourth, ignoring how material arrives, since a partial truckload usually bills at a full haul fee.

What the truck can legally carry

Federal law caps the load before your supplier does. Under 23 CFR 658.17, a single axle may carry 20,000 pounds, a tandem 34,000, and gross vehicle weight on the Interstate System 80,000. The Bridge Gross Weight Formula, W = 500(LN/(N−1) + 12N + 36), caps a three-axle group spanning 25 feet at 54,750 pounds. The axle limits cap the same truck at 20,000 + 34,000 = 54,000. The lower figure governs; the two land within 750 pounds of each other. Subtract a tare of 28,000 to 32,000 pounds and legal payload is 22,000 to 26,000 pounds, or 11 to 13 short tons. The 27.3-ton order above is three loads.

Light material never reaches that limit. A 15-yard body of bark mulch at 25 lb/ft³ holds 405 ft³ × 25 = 10,125 pounds, roughly 5.1 tons. The box fills long before the axles complain, which is why mulch is priced by the yard.

The pile looks too small: measuring the shortfall

It always looks too small, and there is a geometric reason. Volume grows as the cube of a pile's dimensions, so doubling the material raises the peak by only 26 percent. Your eye reads height. Measure instead.

Walk the base and measure its circumference, then divide by 6.2832 for the radius. Measure peak height against a level string. Loose volume is (1/3) × π × r² × h in cubic feet, divided by 27. A pile 44 feet around with a 5-foot peak gives r = 7.00 ft and 257 ft³, or 9.5 loose cubic yards. Check the geometry: tan θ = 5 ÷ 7 puts the slope at 35.5 degrees, inside the 33-to-40-degree repose range for crushed aggregate. A 13.0-ton ticket at 110 lb/ft³ predicts 26,000 ÷ 2,970 = 8.8 loose yards, and cone measurement carries 10 to 15 percent error. That delivery is fine.

The shortfall that matters sits in the installed work. Spread everything, compact it, then probe depth on a grid. Suppose you covered 1,000 of the 1,200 ft² at 3 inches instead of 4. The remainder is (1,000 × 1/12) + (200 × 4/12) = 150 ft³, or 5.6 compacted cubic yards. At 1.77 tons per compacted yard that is 9.8 dry tons, about 10.2 tons on the ticket once moisture is added. One more load.

Turn the scale ticket into your own density

Keep a log. Per delivery: date, material designation and spec (say "#57, AASHTO M 43"), ticket number, gross and tare and net weight, rainfall in the previous 48 hours, loose yards measured on site, square feet covered, average compacted depth achieved.

The number you are building is net tons divided by compacted cubic yards installed. After five or six tickets that ratio is your quarry's real conversion factor for your material, and it moves with the season: free moisture alone can swing a ticket 4 to 8 percent between a wet week and a dry one, the same size as the discrepancy most buyers write off as being shorted. The routing card taped inside my rig lists every gain stage and what it does to the level, and this log is that card for a driveway. Bring the derived factor to the next order and quote it back to the yard.

Frequently asked questions

Is one yard of gravel one ton?

No. One loose cubic yard of gravel weighs roughly 2,500 to 2,900 pounds, or 1.25 to 1.45 short tons, so the shortcut misses by 25 to 45 percent. It only nears accuracy for light organics such as damp compost near 75 pounds per cubic foot.

Are 20 tons the same as 20 yards?

No. Twenty short tons of crushed stone at 105 pounds per cubic foot is about 14.1 loose cubic yards, roughly 30 percent less volume than 20 yards. Twenty tons of bark mulch at 15 pounds per cubic foot is about 99 cubic yards, nearly five times more.

How many yards are in a one-ton dump?

The "one-ton" label describes a truck class rather than a load. One short ton of crushed stone occupies about 0.71 loose cubic yards, topsoil 0.91, mulch 2.5 to 4.9. One-ton dump bodies commonly carry 4,000 to 6,000 pounds, so read the door-jamb payload sticker first.

How many yards are in a ton of dirt?

Unscreened fill dirt runs about 90 to 110 pounds per cubic foot, giving 0.67 to 0.82 loose cubic yards per short ton. Clay and rock push it heavier, and a soaked load gains around 20 percent. NIST Handbook 130 Section 2.29(a) lets suppliers price fill dirt either way.

How many yards are in a ton of soil?

Screened topsoil is lighter than fill dirt, near 75 to 90 pounds per cubic foot, so one short ton is roughly 0.82 to 0.99 loose cubic yards. USDA-NRCS reports undisturbed soil bulk density between 1.0 and 1.4 g/cm³, or 62 to 87 pounds per cubic foot before screening.

How many yards are in a ton of 3/4-inch stone?

Washed ¾-inch stone (#57) runs 95 to 105 pounds per cubic foot loose, so one short ton is 0.71 to 0.78 loose cubic yards. Being open-graded, it barely densifies under a plate compactor. One ton covers 58 to 63 square feet at a 4-inch depth.

How should compaction change an aggregate order?

Calculate compacted volume first, then convert upward. A dense-graded base placed at 95 percent of its Proctor maximum occupies about 1.24 times more space loose in the truck than installed, so 14.8 compacted cubic yards needs roughly 18.4 loose yards. Open-graded #57 needs no allowance.