Soil & Compost Volume Calculator
Litres, bags and the weight nobody checks.
Work out Soil & Compost Volume. Litres, bags and the weight nobody checks. States the assumption instead of hiding it.
Soil needed
864 litres
0.864 m³ · about 605 kg
Bagged compost is sold by volume and delivered loose soil by weight or cubic metre, so both are given. Bulk delivery is dramatically cheaper above about a cubic metre, which is only four or five bags' worth — the crossover comes sooner than people expect. The weight assumes a peat-free compost-based mix at around 700 kg per cubic metre. Topsoil and loam are heavier, often 1,200 to 1,500 kg per cubic metre, which matters if the bed sits on a balcony or a roof. Fresh compost settles by 10 to 20% in the first season as it breaks down. Overfilling slightly at planting saves topping up later, and mounding the middle sheds water off the surface rather than into the crowns.
How the Soil & Compost Volume Calculator works
Volume for a raised bed or border in litres, cubic metres and cubic feet, with the bag count and the filled weight. Bagged compost is sold by volume and bulk soil by the cubic metre, so both are given.
Also known as: how much soil for a raised bed · how many bags of compost do i need · topsoil for a border calculator · cubic metres of soil to bags
Frequently asked questions
How much soil do I need for a raised bed?
Length times width times depth. A 2.4 by 1.2 m bed filled to 30 cm needs about 864 litres — roughly 22 bags of 40 litres, which is usually the point at which bulk delivery becomes much cheaper.
How many bags of compost is a cubic metre?
Twenty-five bags of 40 litres, or about eighteen of the common 60-litre size. Bulk delivery is typically a third of the bagged price per litre once you are buying a cubic metre or more.
How deep should a raised bed be?
30 cm suits most vegetables and 45 to 60 cm suits root crops and shrubs. Deeper beds dry out more slowly and need far more filling, so many gardeners fill the bottom third with coarse material and the rest with growing medium.
How much does garden soil weigh?
Compost-based mixes run around 700 kg per cubic metre; topsoil and loam are 1,200 to 1,500. It matters on balconies and roof terraces, where the loaded weight can exceed what the structure is rated for.
Why does my bed sink after the first season?
Fresh compost settles 10 to 20% as it decomposes. Overfilling slightly at planting saves topping up later, and mounding the centre helps water shed off the surface rather than sitting around plant crowns.
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