Topsoil calculator
Work out how much topsoil you need for a lawn, raised bed or border. Enter the area and the depth and this calculator gives you the volume, the weight in tonnes and the number of bulk bags.
Topsoil calculator
Enter your measurements in metres. Everything updates as you type, and nothing is sent anywhere.
Based on a screened topsoil density of about 1.5 tonnes per cubic metre and bulk bags of around 800kg. A new lawn needs about 100mm of topsoil, planting beds 150mm or more, and raised beds however deep you build them.
Common questions
How much topsoil do I need?
Multiply the area by the depth for the volume, then by about 1.5 to get the weight in tonnes. For a new lawn allow about 100mm depth; for planting beds 150mm or more.
How many bulk bags of topsoil is a tonne?
A bulk bag of topsoil weighs roughly 800kg, so a little over one bag makes a tonne. One bag is about half a cubic metre, enough to cover around 5 square metres at 100mm deep.
These are independent guide prices based on typical UK jobs in 2026. Your actual cost depends on your property, spec, access and where you live. Always get at least three written quotes before committing. These quantities are a guide to help you order. Always round up and check with your supplier before buying.