Gravel Calculator
Gravel is worked out by volume and sold by weight, so this does both — cubic yards from your measurements, then tonnage using the material density, which is the number your supplier will want.
Gravel needed
6.62short tons
- Cubic yards
- 4.67
- Cubic feet
- 126.0
- Cubic metres
- 3.57
- Weight
- 6.62 short tons
- Tonnes
- 6.00
- Includes a 5% waste allowance. The bare figure is 4.44 cubic yards.
- Aggregate is normally sold by the ton, so the weight figure is the one to quote your supplier.
- Densities are mid-range trade figures. Loose material settles and its weight changes with moisture, so treat the tonnage as an estimate.
About the gravel calculator
Aggregate is quoted and delivered by the ton. That means a gravel calculation is really two steps: get the volume from the area and depth, then convert it to weight. Gravel runs about 1.4 short tons to the cubic yard, crushed stone slightly less, and sand varies with how wet it is.
Depth depends on what the surface has to carry. Two to three inches suits a footpath or a decorative bed. A driveway wants four inches or more over a compacted sub-base, and anything carrying heavy vehicles needs a proper layered build-up.
Densities here are mid-range trade figures. Real material shifts with stone size and moisture, so treat the tonnage as a figure to order against rather than an exact weight.
What it works out
- Tonnage, which is how aggregate is sold
- Volume in cubic yards, metres and feet
- Gravel, crushed stone and dry or wet sand
The formula
Tons = (Length × Width × Depth ÷ 27) × Density per cubic yard
Gravel is calculated by volume and sold by weight, so this is a two-step job. Work out the cubic yards from the area and depth, then multiply by the material's density to get tonnage — which is the number your supplier will actually want.
Density is where the two materials part company. Gravel runs about 1.4 short tons to the cubic yard and dry sand about 1.35, but wet sand is nearer 1.6 because of the water it is holding. Suppliers quote from their own figures, so treat the tonnage here as an estimate to order against rather than a precise weight.
Depth depends on what the surface has to carry. Two to three inches is fine for a footpath or a decorative bed. A driveway wants four inches or more, usually over a compacted sub-base, and anything carrying heavy vehicles needs a proper build-up in layers.
- Length and Width
- The area being covered. For an irregular shape, split it into rectangles and add them up.
- Depth
- Finished depth of the layer. Aggregate compacts, so it will settle slightly below what you spread.
- Density
- Weight per cubic yard, which differs by material and by how wet it is.
A worked example
A thirty by twelve foot driveway, laid four inches deep in gravel.
That works out to 6.62 short tons.
- Cubic yards
- 4.67
- Cubic feet
- 126.0
- Cubic metres
- 3.57
- Weight
- 6.62 short tons
- Tonnes
- 6.00
Questions
How many tons of gravel do I need?
Work out the cubic yards — length times width times depth, divided by 27 — then multiply by about 1.4 for gravel. A thirty by twelve foot driveway at four inches is 4.4 cubic yards, so roughly six tons.
How much area does a ton of gravel cover?
About 100 square feet at two inches deep, or 50 square feet at four inches. That varies with stone size, since larger stone leaves more air between pieces.
How deep should gravel be for a driveway?
Four inches of surface gravel is the usual minimum, and most driveways are built up in layers over a compacted sub-base rather than laid in one go. A footpath or decorative bed is fine at two to three inches.
How much does a yard of gravel weigh?
Around 2,800 pounds, or 1.4 short tons. Crushed stone is slightly lighter at about 1.35 tons, and wet material is heavier than dry because of the water it carries.
Should I order by the ton or by the yard?
Ask your supplier which they quote in — most sell aggregate by weight, but some sell by volume, and converting between the two using their density rather than a general figure avoids an argument on delivery day.
How much extra gravel should I order?
Five to ten per cent. Aggregate compacts as it is rolled, the subgrade is never perfectly level, and a short delivery means paying a second haulage charge for a small top-up load.