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Landscaping · topsoil quantity

Topsoil Calculator

Start with the actual area and topsoil depth to calculate cubic metres and litres. Then convert to tonnes or whole supplier bags only from product information you actually have.

0% extra by defaultNo fixed soil depthNo generic density or bulk-bag size
Landscaping illustration for the Topsoil Calculator

Measure the soil layer, then choose the supplier conversion

The universal calculation is area × chosen depth. For ordering, use either a real supplier/product density or the stated volume of the exact bag you intend to buy.

How do you want to convert the topsoil volume?
m²
Use the measured lawn, border, bed or other soil footprint.
mm
Enter the depth required by the actual project, specification or supplier guidance.
t/m³
Enter a real figure for the topsoil you are ordering; do not assume 1.3 t/m³.
%
Optional. Starts at 0%; choose an allowance only if the measured job needs one.
No settlement or compaction factor is hidden in the result. This tool calculates the soil layer you specify. It does not invent topsoil depth, soil density, bag size, settlement or waste.
Enter the actual area, chosen soil depth and supplier conversion.The results will keep base volume, optional allowance and purchasing conversion separate.

How the topsoil quantity is built

01Measure the footprint

Use the actual square metres that will receive topsoil.

02Choose the soil depth

Lawn preparation, borders, raised beds and levelling can require different depths.

03Convert with real supplier data

Use product density for tonnes or the exact stated bag volume for whole bags.

Core formula

Base topsoil volume = area (m²) × depth (mm ÷ 1,000). Litres = m³ × 1,000.

Why there is no 100 mm default

There is no single topsoil depth that suits every project. The required layer depends on what is being established or levelled, the existing ground and the project specification, so the calculator asks for the depth that applies to the actual job rather than silently choosing one.

Why density and bulk-bag size start blank

Topsoil products are not sold at one universal density or in one universal bag volume. Suppliers may quote volume, weight, coverage or a combination of these. Use the current specification for the exact product you intend to order.

Worked calculation — volume only

If an area is 30 m² and the chosen topsoil depth is 120 mm, the base volume is 3.600 m³, or 3,600 litres. No tonnes or bags should be inferred until a real density or bag volume is supplied.

What the two purchasing modes mean

Density → tonnes

Multiply the calculated volume by the actual product density you enter. The calculator does not impose a delivery-unit rounding rule because suppliers quote tonnes differently.

Bag volume → whole bags

Divide the required litres by the supplier’s stated litres per bag, then round the final purchasing quantity up to whole bags.

Optional bag weight

If the exact bag weight is also published, the calculator can show the nominal tonnes represented by the final whole bags. Weight is never guessed.

Quantity estimate, not horticultural or ground design. This calculator does not decide a suitable soil type, depth, drainage, preparation method, settlement factor or planting specification. Check the project requirements and exact supplier product before ordering.

Continue the landscaping workflow

Lawn finishTurf Roll CalculatorOnce the soil quantity is known, calculate turf separately from the actual lawn area and roll coverage.Surface layerMulch & Bark CalculatorKeep topsoil volume separate from any mulch or bark layer above it.Alternative surfaceGravel CalculatorUse the loose aggregate workflow for gravel rather than applying soil assumptions.GuidesLandscaping GuidesPlan paving, fencing, turf, soil and other landscaping quantities as separate materials.Volume referenceCubic Metre Conversion GuideCheck the relationship between square metres, depth, cubic metres and litres.Density referenceBulk Density GuideUnderstand why volume cannot become tonnes without a material-specific density.

Frequently asked questions

How deep should topsoil be?

There is no single depth for every lawn, border, raised bed or levelling job. Use the depth required by the project, specification or supplier guidance for the actual use.

What bulk density should I use?

Use current product or supplier information for the exact topsoil. Soil composition and moisture can change the relationship between cubic metres and tonnes.

Is every topsoil bulk bag the same size?

No. Suppliers sell different bag volumes and weights. Enter the stated litres for the exact bag you intend to buy, and only add its weight if that figure is also provided.