Home / Information & advice / Topsoil & compost / Choosing topsoil / Calculating topsoil requirements
Quick links:
- Measuring your area
- Topsoil calculator
- Loose topsoil
- Recommended topsoil depths
- Selecting the right topsoil
- Suggested products
How to measure your area
To calculate how much topsoil you need, simply measure the dimensions of the area you wish to cover and multiply this by the depth required.
Measuring in metres is simplest, as this will give you the volume of topsoil you need in cubic metres.
For example:
A site has an area of 10m x 15m and needs a coverageof 150mm.
10 x 15 x 0.15 = 22.5m3
Once you know the volume in cubic metres you can work out how many bulk bags are needed by dividing by the volume in a bag.
Bulk bags vary in size, so do check how much is in a bag when comparing different products.
Generally the volume in cubic metres or litres, and/or bulk bag dimensions should be made available by suppliers; weight is not applicable to the above calculations.
Topsoil calculator
You can also enter your measurements into Rolawn’s handyTopsoil Calculatorwhich will give you an indication of how many bags of the differentRolawn task-specific topsoilsare needed. The calculator will also convert yards, feet & inches if your measurements aren’t in metres and millimetres. Do make sure you select the correct units in the calculator.
Loose topsoil
Rolawn topsoil is sold in bulk bags, however if you need to calculate the tonnage required when buying loose topsoil, you’ll need to check the bulk density of the product, as this will vary depending on the type of topsoil and its make up. As a general rule, a tonne of a standard topsoil equals approximately 0.67m3. Divide the cubic metres required by 0.67 to give you the tonnage.
Recommended depths
The recommended depth of imported topsoil required will depend on the site, the existing soil and what you are going to use the area for. In new properties the soil is often shallow and poor quality, therefore importing the full recommended depth of topsoil may be required.
If the soil structure is poor, incorporating a soil improver may be the best option. If your existing soil is reasonably good quality, a shallower layer of new topsoil may be all that’s required to bring it up the required depth or assist with providing a level surface and good tilth.
Lawns
The recommended depth oftopsoil for creating lawnsfrom turf or seed is 100 to 150mm.
General gardening
150 to 200mm oftopsoilis usually sufficient for most planting.
Vegetable growing
The depth oftopsoil for growing vegetableswill vary depending on what you plan to grow. Root vegetables such as potatoes and carrots will need 300 to 400mm, whereas vegetables such as salads, beans and courgettes will need a depth of 150 to 200mm.
Use ourProduct Calculatorto calculate how much topsoil you need.
Selecting the right topsoil
Rolawn offers a range of market-leading topsoils that are safe, fertile and horticulturally focused.
You can choose either a general purpose blended loam or one of our task-specific topsoils, each of which is blended with a particular horticultural purpose in mind.
Find out more in our 'Selecting the right topsoil' video
Lawn care reminders to your inbox
You can alsosign up to our newsletterto receive free seasonal lawn care advice and reminders of essential maintenance, as well as general horticultural advice and special offers from Rolawn.