Mulch & Topsoil Calculator
Free toolEnter the area to cover (or the length and width) and the depth of the layer. We calculate the volume in m³, the total liters, and how many bags you need to buy, based on the bag size you choose.
Result
- Volume:
- Liters:
- Bags needed:
How to use it
- Enter the area to cover or the length and width of the bed.
- Choose the material: mulch, topsoil or substrate, and adjust the depth if you like.
- Set the bag size and read the litres and bags needed.
What it works out and how
Volume in litres is the area in square metres times the depth in centimetres times 10, since one square metre one centimetre deep is 10 litres. Default depths are 6 cm for mulch, 25 cm for topsoil and 30 cm for substrate. Bags are obtained by dividing the litres by the bag capacity and rounding up.
Frequently asked questions
What depth of mulch is right?
Between 5 and 8 cm. Less will not suppress weeds; much more can keep water and air from reaching the soil.
Bags or bulk?
From about 500 litres, ordering in bulk or in a bulk bag is usually much cheaper than small bags.
Does the material settle?
Yes. Soil and substrate lose volume once watered and compacted; add 10–15% if you need an exact finished level.