Calculator
Topsoil calculator for new turf
Topsoil gives new turf something good to root into. Use our calculator to work out roughly how much you'd need, then read on for how deep it should be.
How much topsoil?
Enter the lawn area and choose a depth.
3.0 m³ of topsoil
Roughly 4.2 tonnes, based on about 1.4 tonnes per cubic metre. Damp soil weighs more, so treat this as a guide.
The sum behind it
Volume is area times depth. Convert the depth to metres first: 10 cm is 0.1 m. So a 30 m² lawn at 10 cm deep needs 30 × 0.1 = 3 m³ of topsoil.
Topsoil is often sold by the tonne. A cubic metre usually weighs somewhere around 1.3 to 1.5 tonnes, more when it's wet, which is why the calculator gives the weight as a rough guide.
Which depth?
| Depth | When it's used |
|---|---|
| 5 cm | A top-up over decent existing soil, or filling shallow dips |
| 10 cm | A typical bed for new turf where the soil is thin or tired |
| 15 cm | Poor, stony or heavy clay ground, or after building work |
| 20 cm or more | Raising a low area or replacing an artificial grass base |
Do you always need topsoil?
No. If your soil is already good, it may just need loosening and levelling. Our guide to laying turf without topsoil explains when you can skip it and when you really shouldn't.
Topsoil and levels
Adding topsoil raises the ground. Before adding a lot, check the finished level against paths, patios and the damp-proof course of the house, which soil should always stay below. When we lay a lawn, we set the levels for you.
Common questions
How much does a bulk bag of topsoil cover?
It depends on the bag size and depth. Check the volume printed on the bag and divide by your depth in metres to get the area it covers.
Does topsoil settle?
A little. Firming it as it's spread keeps settling to a minimum.