Gravel calculator: tons, cubic yards and truckloads

Quick answer

A cubic yard of gravel weighs roughly 1.1 to 1.45 short tons. Treesdale Landscape lists 1.1 tons per cubic yard for pea gravel and 1.29 for its 2B limestone, and North Bay Materials states 2500 to 2900 lb. An area of 15 × 10 ft covered 2 in deep takes 1.02 cubic yards with 10 percent extra, about 1.32 tons of crushed stone.

What this calculator does

Quarries and landscape yards sell gravel by the ton or tonne, by the cubic yard or cubic metre, by the truckload or in bags. This calculator gives all four, so you can order in the unit your supplier uses.

It has two modes. Area is for a layer of stone on a path, a driveway or under a patio or shed. Trench is for a French drain: a trench filled with stone around a perforated pipe, where the pipe takes its own volume out of the stone.

The volume is exact geometry. The weight is an estimate, because it depends on the stone, the size of the pieces and the moisture. The number of truckloads depends on what the supplier puts on one truck, which you enter.

How to use it

1. Choose metric or US units. In US units you can type feet and inches, such as 12' 6", and fractions.
2. Choose Area or Trench.
3. Area: enter the length, the width and the depth of the layer. Trench: enter the length, the width, the depth of stone and the diameter of the pipe, or 0 without a pipe.
4. Choose the stone. This fills in an example bulk density, which you can replace with the figure from your supplier.
5. Enter what one truck delivers, as your supplier states it, and the size of a bag if you buy bags.
6. Set the allowance and select Calculate.

How the result is calculated

1. Area: volume = length × width × depth.
2. Trench: volume = length × (width × depth − π × (pipe diameter ÷ 2)²).
3. Volume to order = volume × (1 + allowance ÷ 100), rounded up to 0.01 m³ or 0.01 cubic yard.
4. Weight = volume to order × bulk density, rounded up to 0.01 tonne or short ton.
5. Truckloads = weight ÷ load of one truck, rounded up to a whole load.
6. Bags = volume to order ÷ volume of one bag, rounded up to a whole bag.

Depths and widths in millimetres or inches are converted before the multiplication. One cubic yard is 27 cubic feet. A short ton is 2000 lb, or 907 kg; a tonne is 1000 kg.

Worked example

A path is 5 m long and 3 m wide and gets 50 mm of crushed stone. Volume: 5 × 3 × 0.05 = 0.75 m³. With 10 percent allowance: 0.825 m³, shown as 0.83 m³. At 1500 kg per m³ the weight is 1237.5 kg, shown as 1.24 t: 1 truckload of 10 t, or 825 ÷ 500 = 1.65, so 2 bulk bags of 500 L.

In US units: 15 ft by 10 ft with 2 in of crushed stone is 15 × 10 × (2 ÷ 12) = 25 cu ft. With 10 percent allowance that is 27.5 cu ft, which is 27.5 ÷ 27 = 1.02 cubic yards. At 95.6 lb per cu ft the weight is 2629 lb, or 1.32 short tons: 1 truckload of 10 tons, or 55 bags of 0.5 cu ft.

A French drain 30 ft long, 12 in wide, with 18 in of stone around a 4 in pipe: 30 × (1 × 1.5 − 3.14159 × (2 ÷ 12)²) = 30 × 1.4127 = 42.4 cu ft. With 10 percent allowance, 46.6 cu ft or 1.73 cubic yards, about 2.23 tons of crushed stone.

Stone presets and where the weights come from

Suppliers publish different weights for similar stone and describe them as approximate. The presets use these figures; replace them with the weight on your quote.

Stone sizes have different names in different regions, so compare the description, not only the name. Many calculator websites use higher weights, and compacted base material is denser than the loose stone on a truck. If your supplier sells by the ton, ask for the weight of the stone you order.

Bag size examples: a 500 L bulk bag (Mainland Aggregates, UK) and a 0.5 cu ft bag of 50 lb (Quikrete all-purpose gravel, as listed by a retailer).

Common mistakes

• Entering the depth in feet or metres. A layer of 2 in is one sixth of a foot, and 50 mm is 0.05 m; the calculator expects inches or millimetres.
• Comparing a price per ton with a price per cubic yard without converting. Use the volume and the weight from the result.
• Assuming every truck carries the same load. Ask the supplier, and check the weight against the load limit of your own trailer.
• Ordering the exact volume for a base that will be compacted. Compacted stone takes up less space than loose stone on the truck.
• Forgetting the pipe in a French drain, or subtracting a pipe that is not there.