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Topsoil Calculator

Estimate topsoil volume, cubic metres, cubic yards, bags, tonnes, truckloads, waste, and optional material cost for lawns, gardens, raised beds, landscaping areas, and custom soil-placement projects.

Project Measurements

Select the project shape, units, soil depth, and purchasing method.

Measurement system

Topsoil density

Rectangle

Circle

Raised bed

Custom area

Custom volume

Project length

Enter length in metres.

Project width

Enter width in metres.

Area diameter

Enter diameter in metres.

Bed length

Enter length in metres.

Bed width

Enter width in metres.

Number of raised beds

Total surface area

Enter area in square metres.

Known topsoil volume

Enter volume in cubic metres.

Topsoil depth

Enter depth in centimetres.

Density in kg/m³

Loose screened topsoil density estimate.

Bag size

Settlement and waste

Allows for settlement, uneven grading, and handling losses.

Truck capacity in m³

Used to estimate delivery loads.

Cost per cubic metre

Optional bulk topsoil cost per cubic metre.

Cost per bag

Optional bagged-topsoil cost estimate.

Your topsoil estimate will appear here

Enter the area, depth, density, bag size, and waste allowance.

Estimated topsoil requirement

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Including settlement and waste

Surface area —

Base volume —

Volume with allowance —

Selected density —

Topsoil bags

—

Estimated weight

—

Delivery loads

—

Applied depth

—

Settlement allowance

—

Estimated topsoil material cost —

This calculator provides a planning estimate. Actual volume and weight vary with moisture, compaction, organic content, screening, supplier density, uneven ground, settlement, delivery method, and whether the soil is sold loose, heaped, compacted, or by bag.

What Does the Topsoil Calculator Estimate?

The calculator converts project area and soil depth into a topsoil volume. It then applies settlement and waste, estimates bags, bulk weight, delivery loads, and optional material cost.

Included estimates

Rectangular and circular landscaping areas
Multiple raised garden beds
Custom area or known soil volume
Cubic metres, cubic yards, and cubic feet
Topsoil bag quantity
Estimated kilograms, tonnes, pounds, or US tons
Delivery-truck loads
Optional bulk or bagged-soil cost

How Deep Should Topsoil Be?

The correct depth depends on the existing ground, intended plants, drainage, soil quality, and whether topsoil is being added for establishment or complete replacement.

General planning depths

2–5 cm: Light lawn topdressing
5–10 cm: Lawn establishment over prepared subsoil
15–30 cm: General garden beds and planting areas
30 cm or more: Raised beds, deep-rooted planting, or poor existing soil
Always confirm requirements for the selected plants and site conditions

How to Use the Topsoil Calculator

Select metric or imperial units

Choose the measurement system used for the area, depth, bag size, truck capacity, and price.

Choose the project shape

Calculate a rectangle, circle, group of raised beds, custom area, or known soil volume.

Enter the soil depth

Use the finished topsoil depth required for the lawn, planting bed, or landscaping specification.

Select density, bags, and allowance

Choose a suitable soil density and add an allowance for settlement, uneven grading, and handling.

Review volume, weight, and cost

Use the results to compare bulk delivery with bagged topsoil and confirm final quantities with the supplier.

Typical Topsoil Planning Inputs

Input	Typical planning approach	Why it matters
Topsoil depth	Choose according to lawn, garden, or planting requirements	Directly controls required volume
Bulk density	Often around 1,250–1,600 kg/m³ depending on moisture and composition	Converts soil volume into weight
Settlement allowance	Often 5%–15% for loose placement and uneven ground	Helps maintain the intended final depth
Bag size	Use the exact labelled volume from the selected product	Determines full bags to purchase
Truck capacity	Use the supplier’s practical volume per load	Estimates delivery requirements

Topsoil Calculation Formulas

Rectangular area

Area equals length × width.

Circular area

Area equals π × radius².

Topsoil volume

Volume equals surface area × soil depth.

Bags and weight

Bags equal volume with allowance ÷ bag volume, rounded up. Soil weight equals volume with allowance × bulk density.

Frequently Asked Questions

Multiply the surface area by the required soil depth, then add an allowance for settlement, uneven grading, and handling. The calculator performs these steps automatically.

Divide the waste-adjusted soil volume by the labelled volume of one bag and round up to a whole bag.

Moisture, clay content, sand, organic matter, screening, and compaction can significantly change bulk density and total weight.

Usually yes. Loose soil settles after spreading, watering, and natural consolidation. A 5% to 15% allowance is common for early planning, depending on the project.

Bulk delivery is often more economical for larger volumes, while bags can be more convenient for small areas, limited access, or projects that require easier handling.

No. It estimates topsoil only. Compost, soil conditioner, mulch, drainage layers, fertiliser, and amendments should be calculated separately according to the planting plan.