How do I convert cubic metres to tonnes?

Multiply the volume in cubic metres by the material's density in tonnes per cubic metre (t/m³). For example, 5 m³ of concrete at 2.4 t/m³ equals 12 tonnes. The density varies significantly by material: water is 1.0 t/m³, concrete is about 2.4 t/m³, steel is about 7.85 t/m³, and dry sand is about 1.6 t/m³. Always confirm the exact density with your supplier for critical applications.

How many tonnes is 1 cubic metre of concrete?

One cubic metre of normal-strength concrete weighs approximately 2.4 tonnes (2,400 kg). This figure is the standard bulk density used in structural calculations. Lightweight concrete can be as low as 1.4 t/m³ and high-density concrete can exceed 3.0 t/m³. For most standard residential and commercial pours, 2.4 t/m³ is the accepted value.

Is a metric tonne the same as a ton?

No. A metric tonne (t) is 1,000 kilograms. A short ton (used in the United States) is 2,000 pounds, which equals approximately 907 kg. A long ton (used in the United Kingdom historically) is 2,240 pounds, or about 1,016 kg. In New Zealand and Australia, 'tonne' always refers to the metric tonne of 1,000 kg. This converter uses metric tonnes throughout.

Cubic Metre to Tonne Converter

Convert cubic metres (m³) to metric tonnes for concrete, sand, gravel, soil, steel, asphalt, water, and other common materials. Select a preset material or enter a custom density. Results update instantly.

Formula: Tonnes = Volume (m³) × Density (t/m³). One metric tonne equals 1,000 kg.

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Updated June 2026 Density values sourced from engineering references and material data sheets.

1. Volume

Volume in cubic metres

m³

2. Material

Select material

Custom density (t/m³)

t/m³

Conversion Result

Mass
-
Metric tonnes (t)

Mass in kg

Kilograms

Density used

t/m³

Volume

Cubic metres

Calculation Breakdown

Volume-

Material-

Density-

Formula-

Result-

Unit Equivalents

Metric tonnes (t)-

Kilograms (kg)-

Grams (g)-

Short tons (US)-

Pounds (lb)-

Common Materials: Tonnes per Cubic Metre

Material	Density (t/m³)	1 m³ in tonnes	5 m³ in tonnes	10 m³ in tonnes
Water	1.00	1.00 t	5.00 t	10.00 t
Topsoil (loose)	1.20	1.20 t	6.00 t	12.00 t
Sand (dry)	1.60	1.60 t	8.00 t	16.00 t
Gravel (dry)	1.80	1.80 t	9.00 t	18.00 t
Asphalt	2.30	2.30 t	11.50 t	23.00 t
Concrete (normal)	2.40	2.40 t	12.00 t	24.00 t
Aluminium	2.70	2.70 t	13.50 t	27.00 t
Steel	7.85	7.85 t	39.25 t	78.50 t

How to Convert Cubic Metres to Tonnes

Volume and mass are different physical quantities and cannot be converted without knowing the density of the material involved. Density is the mass per unit volume, expressed here in tonnes per cubic metre (t/m³). The conversion formula is:

Mass (t) = Volume (m³) × Density (t/m³)

For example, 5 cubic metres of concrete with a density of 2.4 t/m³ has a mass of 5 × 2.4 = 12 tonnes. The same volume of dry sand (density 1.6 t/m³) would weigh 8 tonnes. Because the density varies so widely between materials, it is essential to select the correct material or enter the correct density for your specific application.

Metric Tonnes vs Tons

In New Zealand, the standard unit of mass in this context is the metric tonne (t), which equals 1,000 kilograms. This is sometimes written as 1 Mg (megagram) in scientific notation. The metric tonne is distinct from:

The US short ton: 2,000 pounds (approximately 907 kg)
The UK long ton: 2,240 pounds (approximately 1,016 kg)

Unless otherwise specified, construction suppliers and engineers in New Zealand and Australia always mean metric tonnes. This converter uses metric tonnes throughout.

Material Density Notes

Densities given in this converter are standard reference values for typical conditions. In practice, density can vary depending on moisture content, compaction level, particle size, and composition. For example:

Dry sand is typically 1.4 to 1.7 t/m³; wet or compacted sand can reach 1.9 to 2.1 t/m³.
Topsoil density varies with organic content and moisture, commonly 0.9 to 1.6 t/m³.
Concrete density depends on aggregate type; lightweight concrete can be as low as 1.4 t/m³; high-density concrete can exceed 3.0 t/m³.
Steel is highly consistent at approximately 7.85 t/m³ for carbon and low-alloy steels.

For critical engineering or procurement applications, always confirm the actual density with your material supplier or laboratory test data. Use the custom density field in this converter to enter a precise value.

Worked Example

A driveway pour requires 5 m³ of concrete. The concrete supplier quotes a standard density of 2.4 t/m³. How many tonnes is this?

Mass = 5 × 2.4 = 12 tonnes

If you are ordering from a ready-mix supplier, this equates to 12,000 kg. Trucks typically carry 8 to 9 tonnes per load, so two truck loads would be needed. You would also need to confirm the delivered volume, as settling and waste should be factored into your order.

Related Calculators

Essential Calculators hub
Cubic Metre Calculator: calculate volume from dimensions.
Density Calculator: solve for density, mass, or volume.
Concrete Weight Calculator: detailed concrete mass by slab or pour dimensions.
Weight Converter: convert between kg, tonnes, pounds, and other mass units.

Sources and method: Density values sourced from NZS 3101:2006 (concrete), engineering materials references (Machinery's Handbook), and commonly accepted bulk material data. Formula: Mass (t) = Volume (m³) × Density (t/m³). One metric tonne = 1,000 kg. One short ton (US) = 0.9072 t. One pound = 0.00045359 t.

This converter provides reference estimates using standard density values. Actual material densities vary by supplier, grade, moisture content, and compaction. Confirm specific densities with your supplier for procurement or structural calculations.