Work out how much topsoil, compost, mulch or gravel to buy for a bed, in cubic metres and bags.
How this works
Volume = length x width x depth. Mulch goes on 5 to 7.5 cm deep, compost 5 cm as a top dressing, topsoil 10 to 15 cm, decorative gravel 4 to 5 cm. Bags are usually 50 to 70 L and a bulk bag holds about 0.75 m³.
Questions people ask
How do I use the Garden Soil and Mulch Calculator?
Fill in the fields, starting with “Length”, “Width” and “Depth”, and change any other options that match your home. The answer, a drawing and practical tips update as you type, and the Copy link button saves your numbers in a link you can share.
Is the Garden Soil and Mulch Calculator free?
Yes. The Garden Soil and Mulch Calculator is free, with no sign-up, and works on phones, tablets and computers. The results are estimates to help you plan, so check with a qualified professional before structural, electrical, gas or plumbing work.