Gravel Calculator
Inputs
| Area | 10 m² |
|---|---|
| Depth | 5 cm |
| Material | Gravel (≈1.5 t/m³) |
Gravel Calculator
Estimate the volume and weight (tonnage) of gravel or aggregate needed to fill an area to a given depth, for driveways, paths, drainage, and landscaping.
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Details
Covering 10 m² to a depth of 5 cm needs about ... of material, weighing approximately ....
Gravel
Ordering gravel, sand, or crushed stone comes down to two numbers: the volume needed to fill the space, and the weight that volume represents — because aggregate suppliers sell by weight. Both follow directly from the area you want to cover, the depth of the layer, and the bulk density of the material.
The volume × density method
First find the volume. Multiply the surface area by the depth of the layer, keeping both in metric base units so the result lands in cubic metres:
volume (m3)=area (m2)×depth (m)Then convert that volume to weight using the material's bulk density, expressed in tonnes per cubic metre. Multiplying by 1000 gives the answer in kilograms:
weight (kg)=volume (m3)×density (t/m3)×1000Typical loose bulk densities are about 1.5 t/m³ for gravel, 1.6 t/m³ for sand and crushed stone, and 1.3 t/m³ for topsoil. Real values shift with moisture and stone size, so the tonnage is a close estimate rather than an exact figure.
First find the volume. Multiply the surface area by the depth of the layer, converting to feet so the result lands in cubic yards (1 cubic yard = 27 cubic feet):
volume (cu yd)=27area (sq ft)×depth (ft)Then convert that volume to weight using the material's bulk density, expressed in pounds per cubic yard:
weight (lb)=volume (cu yd)×density (lb/cu yd)Typical loose bulk densities are about 2530 lb/cu yd for gravel, 2700 lb/cu yd for sand and crushed stone, and 2200 lb/cu yd for topsoil. Real values shift with moisture and stone size, so the tonnage is a close estimate rather than an exact figure.
Worked example
A 10 m² area to be covered with gravel at a depth of 5 cm:
volumeweight=10×0.05=0.5 m3=0.5×1.5×1000=750 kgSo this patch needs half a cubic metre of gravel, weighing about 750 kg, or three-quarters of a tonne.
A 108 sq ft area to be covered with gravel at a depth of 2 inch:
volumeweight=27108×0.167=0.67 cu yd=0.67×2530=1650 lbSo this patch needs about two-thirds of a cubic yard of gravel, weighing about 1650 lb, or three-quarters of a ton.
Choosing a depth
The depth drives the quantity directly — double the depth and you double both the volume and the tonnage. A thin decorative layer over a prepared base might be 4–5 cm, enough to hide the ground beneath. Paths that take foot traffic do better at 5–7 cm. A gravel driveway usually needs a deeper build-up, often 10–15 cm or more across a sub-base and top layer, so it can carry vehicle loads without rutting. The depth drives the quantity directly — double the depth and you double both the volume and the tonnage. A thin decorative layer over a prepared base might be 2 inch, enough to hide the ground beneath. Paths that take foot traffic do better at 2–3 inch. A gravel driveway usually needs a deeper build-up, often 4–6 inch or more across a sub-base and top layer, so it can carry vehicle loads without rutting.
Density by material
Bulk density is what turns volume into weight, and it varies by material. Gravel sits around 1.5 tonnes per cubic metre. Sand and crushed stone pack a little denser at about 1.6. Topsoil is lighter and more variable, near 1.3 when loose. These are loose, as-delivered figures; compacted material weighs more for the same delivered volume. Because density also depends on moisture and grading, order a little extra to allow for settling and uneven ground. Bulk density is what turns volume into weight, and it varies by material. Gravel sits around 2530 pounds per cubic yard. Sand and crushed stone pack a little denser at about 2700. Topsoil is lighter and more variable, near 2200 when loose. These are loose, as-delivered figures; compacted material weighs more for the same delivered volume. Because density also depends on moisture and grading, order a little extra to allow for settling and uneven ground.
For related landscaping volume projects, see the Mulch & Garden Soil Calculator.
Frequently Asked Questions (FAQ)
How much gravel do I need?
Start with the area you want to cover and the depth of the layer. Multiply the area (in square metres) by the depth (in metres) to get the volume in cubic metres. For example, a 10 m² area at a 5 cm (0.05 m) depth needs 0.5 m³ of material. Suppliers then sell that material by weight, so the volume is multiplied by the bulk density to find the tonnage.
Start with the area you want to cover and the depth of the layer. Multiply the area (in square feet) by the depth (in feet) to get the volume, then divide by 27 to convert cubic feet to cubic yards. For example, a 108 sq ft area at a 2 inch (0.167 ft) depth needs about 0.67 cu yd of material. Suppliers then sell that material by weight, so the volume is multiplied by the bulk density to find the tonnage.
How do I convert gravel volume to tonnes?
Multiply the volume in cubic metres by the bulk density of the material. Loose gravel is about 1.5 tonnes per cubic metre, while sand and crushed stone are closer to 1.6, and topsoil is around 1.3. So 0.5 m³ of gravel weighs roughly 0.5 × 1.5 = 0.75 tonnes, or 750 kg. Bulk density varies with moisture and stone size, so treat the result as a close estimate and round up when ordering.
Multiply the volume in cubic yards by the bulk density of the material. Loose gravel is about 2530 pounds per cubic yard, while sand and crushed stone are closer to 2700, and topsoil is around 2200. So 0.67 cu yd of gravel weighs roughly 0.67 × 2530 ≈ 1650 lb, or about three-quarters of a ton. Bulk density varies with moisture and stone size, so treat the result as a close estimate and round up when ordering.
How deep should a gravel layer be?
For decorative coverage over a prepared, weed-suppressed base, a depth of 4–5 cm is usually enough to hide the surface beneath. For paths with foot traffic, aim for 5–7 cm. A gravel driveway typically needs a sub-base plus a top layer totalling 10–15 cm or more so it can carry vehicle loads without rutting. Deeper layers need proportionally more material.
For decorative coverage over a prepared, weed-suppressed base, a depth of about 2 inch is usually enough to hide the surface beneath. For paths with foot traffic, aim for 2–3 inch. A gravel driveway typically needs a sub-base plus a top layer totalling 4–6 inch or more so it can carry vehicle loads without rutting. Deeper layers need proportionally more material.
Disclaimer
This is an estimate based on typical loose bulk densities. Actual quantities vary with material moisture content, stone size and grading, and how much the layer compacts. Bulk densities range roughly 1.3–1.7 tonnes per cubic metre depending on the product. Order a little extra to allow for settling and uneven ground.
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