How much does a cubic metre of topsoil weigh?

Approximately 1.4 tonnes (1,400 kg). This varies with moisture content - wet topsoil can weigh up to 1.7 tonnes per m³.

How much does a bulk bag weigh?

A standard bulk bag contains approximately 0.85 m³ of material. Weight depends on the material - a bag of gravel weighs about 1.5 tonnes, while compost is about 0.45 tonnes.

Why does weight matter for ordering?

Many suppliers sell materials by weight (tonnes) rather than volume (cubic metres). Knowing the density helps you convert between the two to order the right amount.

Do I need to worry about vehicle weight limits?

Yes. A standard pickup can carry about 0.5-1 tonne. A single-axle trailer handles roughly 0.75 tonnes. Delivery lorries typically carry 10-20 tonnes.

Why does the same volume of different materials weigh differently?

Density varies hugely. Gravel is about 1,500 kg/m³, topsoil 1,400 kg/m³, bark mulch 350 kg/m³, and compost 500 kg/m³. Always check weight when ordering delivery.

GardenCalcs

Material Weight Calculator — Volume to Weight Conversion

Convert between volume and weight for common garden materials.

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Volume

How We Calculate This

Weight (tonnes) = Volume (m³) x Density (tonnes/m³). Volume = Weight / Density.

Densities are approximate for loose, dry materials. Wet or compacted materials will be heavier.

Bulk bag calculation assumes standard 0.85 m³ bags commonly available from UK builders merchants.

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Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.