For a drive, a path, a raised bed or a mulch layer you need to know the volume. Enter the length, width and depth and this calculator gives the cubic metres, the litres and, if you tell it the bag size, how many bags to buy.
How to Use It
Measure the length and width in metres and the depth in centimetres. Add a few per cent if the material will settle, such as soil or compost. Enter the bag size in litres if you are buying bags: it is printed on the bag.
A Worked Example
A bed 4 metres by 2.5 metres is 10 square metres. A layer 5 centimetres deep is half a cubic metre, which is 500 litres, or ten 50 litre bags.
Volume and Weight
The calculator gives volume, which is how most bags and bulk bags are sold. Some suppliers sell by weight, and a cubic metre weighs very differently for gravel, soil and bark, so ask them how many tonnes to order.
Questions about Gravel, Soil and Compost Calculator
What depth of gravel do I need?
For paths, around 5 centimetres is common. Drives usually need more, often 5 to 10 centimetres on top of a base layer. Ask your supplier for advice for your project.
How many litres are in a cubic metre?
There are 1,000 litres in a cubic metre. A bulk bag of 500 to 1,000 litres is therefore about half to one cubic metre.
Should I allow extra for settling?
Yes, for soil and compost, which settle over time. A few per cent extra is usual. Gravel settles less, but a little spare is useful.