Key Takeaways
- A cubic metre of gravel weighs about 1.5 to 1.8 tonnes Aggregate Industries (1,660 kg for typical washed stone)
- A tonne is weight; a cubic metre is volume; they are not the same thing
- 1 tonne of gravel occupies about 0.6 cubic metres
- 2 tonnes covers about 24 square metres at 5 cm depth or 12 square metres at 10 cm
- The gravel calculator accepts custom density in tonnes per cubic metre
Cubic yard is a unit of volume equal to a cube measuring 3 feet on each side, commonly used in the US for ordering gravel and other aggregates.
Density in gravel calculations refers to the weight of material per unit volume, typically measured in tons per cubic yard or tonnes per cubic metre.
A cubic metre of gravel typically weighs between 1.5 and 1.8 tonnes, with about 1.66 tonnes (1,660 kg) being a reasonable planning figure for a washed crushed stone. That single number answers most of the metric questions people have about gravel, so this page works through it once and then applies it to tonnes, kilograms, and what a couple of tonnes actually looks like on the ground.
How many tonnes in a cubic metre of gravel?
About 1.66 tonnes for a typical washed stone, commonly quoted between 1.5 and 1.8 tonnes depending on the specific material. This is a density, not a fixed conversion factor: a dense graded material such as crusher run sits toward the top of that range because the smaller particles fill the gaps between the larger stones, while a lighter, more uniformly sized stone sits toward the bottom.
The figure comes from the same density most of this site’s calculators start from, 1.4 US tons per cubic yard Aggregate Industries, converted through to the metric system. Cubic yards and short tons are the units aggregate suppliers in North America quote in, which is why they appear first; the metric figures are derived from them, not the other way round.
How many kilograms of gravel are in a cubic metre?
About 1,660 kg, or between roughly 1,500 kg and 1,800 kg Aggregate Industries depending on the material, which is exactly the tonnage figure above multiplied by 1,000. Kilograms and tonnes describe the same weight at different scales, so once you have one you have the other.
Is 1 ton equal to 1 cubic metre?
No, and this is the mix-up behind most of the confusion. A ton, or a tonne, is a unit of weight. A cubic metre is a unit of volume. The two are only numerically equal for a substance with a density of exactly 1,000 kilograms per cubic metre, which happens to be true for water and is not true for gravel. Gravel is roughly 1.5 to 1.8 times denser than water, so a tonne of it takes up noticeably less than a cubic metre of space, not the same amount.
How much is 1 tonne of gravel, in volume?
About 0.6 cubic metres, typically somewhere between 0.55 and 0.65 cubic metres depending on the material’s density. Divide 1 by the density in tonnes per cubic metre to get this: 1 divided by 1.66 is about 0.60. A denser material, such as crusher run near the top of the range, takes up a little less space per tonne; a lighter one takes up a little more.
What do 2 tonnes of gravel look like?
About 1.2 cubic metres, which is a little more than a cube one metre on each side. Spread out rather than piled up, 2 tonnes covers a useful amount of ground depending on how deep you lay it:
[ORIGINAL DATA]
| Depth | Area 2 tonnes covers |
|---|---|
| 5 cm (about 2 in) | about 24 sq m |
| 10 cm (about 4 in) | about 12 sq m |
| 15 cm (about 6 in) | about 8 sq m |
That is roughly the gravel for a small patio at a typical decorative depth, or a modest path laid a little deeper. As a rough visual reference, 1.2 cubic metres is about the volume of six full-size wheelbarrows, or a pickup bed loaded generously above the rails.
Using your own supplier’s figure
Every number on this page uses 1.4 US tons per cubic yard as the reference density, which converts to about 1.66 tonnes per cubic metre Aggregate Industries. That is a typical planning value, not a measured constant, and the real figure for your material can sit meaningfully outside the 1.5 to 1.8 tonne range, especially for something unusually light like lava rock or unusually dense like a fully compacted road base. If your supplier gives you a density in kilograms or tonnes per cubic metre, the gravel calculator accepts a custom density directly, so every result recalculates from your actual figure instead of the typical one.
Editorial note: This article is reviewed for accuracy and updated regularly. All calculations use standard industry formulas. For the latest density figures, consult your gravel supplier directly.
Frequently asked questions
How many tonnes are in a cubic metre of gravel?
About 1.66 tonnes for a typical washed crushed stone. The range is 1.5 to 1.8 tonnes depending on the material. Dense graded materials like crusher run sit toward the top of that range.
How do I convert cubic metres to tonnes?
Multiply cubic metres by the material’s density in tonnes per cubic metre. For example, 2 cubic metres at 1.66 tonnes per cubic metre equals 3.32 tonnes. The gravel calculator handles this conversion automatically.
How much gravel do I need for a small patio?
For a 10 square metre patio at 5 cm depth, you need about 0.5 cubic metres of gravel, which weighs roughly 0.83 tonnes at typical density. Add 10 percent for waste and compaction.
Is a tonne the same as a cubic metre?
No. A tonne is a unit of weight (1,000 kilograms). A cubic metre is a unit of volume (the space a box one metre on each side occupies). The two are only equal for water, which has a density of exactly 1,000 kg per cubic metre. Gravel is denser, so a tonne takes up less space.