How many tonnes in a cubic metre of sand?

It depends on the type of sand. Sharp sand weighs approximately 1.6 tonnes per cubic metre, while building (soft) sand weighs about 1.5 tonnes per cubic metre. These are approximate densities — actual weight varies with moisture content and compaction. When ordering, always specify whether you want sharp or building sand.

How much does a bulk bag of aggregate weigh?

A standard bulk bag (also called a jumbo bag or ton bag) typically contains approximately 0.85 tonnes (850kg) of material. Despite being commonly called 'ton bags', they rarely contain a full tonne. The actual weight depends on the material density and how the bag is filled. Always confirm the weight with your supplier.

What is MOT Type 1 and how heavy is it?

MOT Type 1 is a crushed limestone or granite aggregate used as a sub-base material for driveways, patios, and building foundations. It has a density of approximately 2.1 tonnes per cubic metre, making it one of the heavier common aggregates. The name comes from the Ministry of Transport specification for road construction materials.

Why does bark mulch weigh so much less than other materials?

Bark mulch has a density of only about 0.3 tonnes per cubic metre because it is lightweight organic material with lots of air gaps. This means a cubic metre of bark mulch weighs just 300kg, compared to 2,400kg for the same volume of concrete. This is important when calculating delivery loads and vehicle payloads.

Should I order by volume (m³) or weight (tonnes)?

Most UK suppliers sell aggregates and sand by the tonne (weight), but you measure the area you need to fill by volume (m³). Use this converter to translate between the two. For example, if you need to fill a 3m³ area with gravel, you will need approximately 5.1 tonnes (3 × 1.7). Always order slightly more than calculated to account for compaction and wastage.

Cubic Metres to Tonnes Converter — m³ to Tonnes

How We Calculate This

This converter uses the density (mass per unit volume) of each material to convert between cubic metres and tonnes. Density values are based on typical UK bulk material specifications and represent loose/uncompacted material as typically delivered.

The formula

Tonnes = Cubic Metres × Density (t/m³)
Cubic Metres = Tonnes ÷ Density (t/m³)

For example, 2 m³ of sharp sand at 1.6 t/m³ = 2 × 1.6 = 3.2 tonnes.

Material densities used

Topsoil: 1.4 t/m³
Sand (sharp): 1.6 t/m³
Sand (building/soft): 1.5 t/m³
Gravel (10-20mm): 1.7 t/m³
MOT Type 1: 2.1 t/m³
Hardcore: 1.9 t/m³
Concrete: 2.4 t/m³
Ballast: 1.8 t/m³
Slate Chippings: 1.5 t/m³
Bark Mulch: 0.3 t/m³

Bulk bag equivalents

We estimate bulk bags at 0.85 tonnes each. This is an industry-standard approximation — actual bulk bag weights vary by supplier and material. The number of bulk bags is rounded up because you cannot order partial bags.

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Last updated: February 2026

All calculations are estimates. Verify with your supplier.