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Compost Calculator

Calculate how much compost you need for your beds and lawns

m²
cm
🇩🇰 All calculations are based on Danish rules, rates, and currency (DKK). This calculator is translated for convenience but applies exclusively to Denmark.

Calculate compost for your garden

Our compost calculator helps you determine how much compost you need to improve the soil in your beds, lawns or vegetable garden. Compost is nature's own fertiliser and soil improver.

Recommended thickness

For annual bed maintenance, a 2-3 cm layer of compost is recommended. For new beds, 5-10 cm is beneficial. For lawns, 1-2 cm is sufficient as thicker layers can smother the grass. The compost should be lightly incorporated into the soil.

Compost weight

Compost weighs about 0.6 kg per litre, which is lighter than regular garden soil. This is due to the high content of organic material and air. Weight varies with moisture – wet compost weighs more than dry.

Benefits of compost

Compost improves soil structure, increases water retention, adds nutrients and promotes healthy soil life with earthworms and microorganisms. It is the most natural and sustainable way to improve your garden. You can make your own compost from garden and kitchen waste.

Frequently Asked Questions

How much compost should you use per m²?

For annual maintenance, 2-3 cm of compost is recommended, equivalent to 20-30 litres per m². For new beds you can apply 5-10 cm, equivalent to 50-100 litres per m². For lawns, 1-2 cm (10-20 litres per m²) is sufficient.

How much does compost weigh?

Compost weighs about 0.6 kg per litre or about 600 kg per cubic metre. It is lighter than regular garden soil (about 1,200 kg/m³) because compost has a high content of organic material and air. Wet compost can weigh up to 0.8 kg per litre.

Can you use too much compost?

Yes, too much compost can lead to over-fertilisation with nutrients like phosphorus and nitrogen, which can harm plants and pollute groundwater. Stick to recommended amounts: 2-3 cm annually for beds and maximum 5-10 cm for new installations.

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