How Many Litres in a Tonne of Soil? Understanding Soil Volume and Weight

Weight vs Volume: What’s the Difference?

When working with soil, it’s easy to get confused between tonnes (a measure of weight) and litres or cubic metres (measures of volume). This matters because soil is often sold by the tonne or by volume, and the two don’t always match up neatly. The conversion between weight and volume depends on the type of soil, how compacted it is, and how much moisture it contains.

In short: a tonne of soil does not always equal the same number of litres, and making the wrong assumption can lead to over-ordering or underestimating how much soil you need.

How Many Litres Are in a Tonne of Soil?

As a general rule, a tonne of standard topsoil equals roughly 750 to 850 litres. That’s the average range when the soil is moderately moist and loosely packed. However, this figure can shift depending on the soil’s composition. Light, dry soil may take up more space per tonne, while dense, wet soil can be heavier and more compact, reducing the volume per tonne.

For rough planning, many suppliers estimate that 1 tonne of topsoil fills about 0.75 cubic metres, which is 750 litres. Always check with your supplier, as they often specify the exact conversion based on the soil they stock.

Factors That Affect Soil Density

The number of litres in a tonne of soil can vary because soil isn’t a uniform material. Several factors influence how much space a tonne of soil will occupy:

• Moisture content: Wet soil weighs more per litre than dry soil.

• Soil type: Clay soil is denser than sandy or loamy soil.

• Organic content: Soils rich in compost or bark are lighter and take up more space per tonne.

• Compaction: Loose soil is fluffier, while compacted soil is more dense and takes up less space.

These differences mean that two tonnes of soil from different suppliers may not fill the same number of planters or beds, even if they’re both labelled as topsoil.

Converting Soil Volume to Weight (and Vice Versa)

If you know how many litres or cubic metres of soil you need, but your supplier sells by weight, you’ll need to convert. Here’s a general guide:

• 1 cubic metre of topsoil weighs between 1.2 to 1.6 tonnes, depending on density and moisture.

• 1 tonne of topsoil = roughly 0.6 to 0.85 cubic metres, or 600 to 850 litres.

Always aim to slightly overestimate to account for settling, waste, or uneven surfaces. It’s better to have a little left over than run short mid-way through the job.

Bulk Bags vs Loose Loads

Soil is often delivered in bulk bags, which are typically sold by volume. A standard bulk bag holds around 700 to 900 litres of soil, depending on how it’s packed. This usually equates to 0.7 to 0.9 cubic metres, or close to one tonne in weight for average topsoil.

If you're ordering a loose load by the tonne (often tipped off a truck), check whether you're being quoted by volume or weight. It’s important to compare like-for-like, especially when budgeting or preparing ground space for delivery.

Soil Volume and Weight Are Not Fixed

One key thing to remember is that soil is not a uniform material, so there's no exact, one-size-fits-all conversion between litres and tonnes. Unlike water, which always weighs one tonne per 1,000 litres, soil varies significantly based on its composition, structure, and water content. This is why two suppliers might give slightly different figures for how many litres you’ll get per tonne — and both can be technically correct.

For example, loose, dry, screened topsoil might give you up to 850 litres per tonne, while a tonne of wet, compacted clay could take up as little as 600 litres. That’s a big difference when you’re filling raised beds or regrading an entire garden.

Use Bulk Density as a Reference

The technical term for the relationship between weight and volume is bulk density — the mass of soil per unit of volume, usually measured in tonnes per cubic metre (t/m³). Typical values for topsoil range from 1.2 to 1.6 t/m³. If you’re trying to be precise, check with your supplier what the bulk density of their topsoil is. Multiply the cubic metres you need by the density to find out how many tonnes to order — or do the reverse to calculate litres from tonnes.

Soil with a high organic matter content will have a lower bulk density, while soil high in clay or with high water saturation will be much heavier per cubic metre.

Tonnes vs Cubic Metres vs Litres: Why It Matters

In the UK, soil is often sold either by the tonne (usually for loose loads) or by volume in cubic metres or litres (typically for bulk bags). This matters because if you're comparing quotes, or trying to mix and match sources, you'll need to convert carefully. A cheaper price per tonne doesn’t always mean better value if that tonne fills significantly less space.

If a bulk bag is advertised as "a tonne bag" but only contains 700 litres of soil, it's not necessarily one tonne in weight — especially if the soil is dry and light. Some suppliers label bags by volume, others by weight, so check which metric is being used to avoid confusion.

Volume Loss After Spreading

It’s also important to remember that soil settles significantly after it's spread. A loose cubic metre of topsoil delivered fresh might appear generous, but after raking, compacting, watering, and planting, it can shrink by 10 to 20 percent. This is especially true for compost-rich or organic blends used in beds and borders. Always order slightly more than your calculation suggests if you're working to a finished level or depth.

Examples of Typical Coverage

To give a rough idea of how far a tonne of soil goes, here are some standard applications (based on average density):

• A tonne of topsoil will cover around 10 square metres at a depth of 75mm

• For turf preparation, a tonne usually covers 6 to 7 square metres at 100mm depth

• For raised beds, a single tonne will fill roughly 0.75 to 0.85 cubic metres, or 750–850 litres, depending on compaction and soil type

If you're planning around bag size, a standard bulk bag of topsoil is usually designed to fill 0.75 cubic metres, or 750 litres — though always check your supplier's spec.

Final Word

There’s no fixed number of litres in a tonne of soil because the weight-to-volume ratio depends on the soil type, moisture, and compaction. As a guide, one tonne of average topsoil fills around 750 litres. To avoid miscalculations, always check your measurements, confirm details with your supplier, and account for natural settling after spreading. Whether you're filling beds, levelling ground, or ordering in bulk, understanding the link between volume and weight helps you order the right amount of soil the first time.