Filling raised beds, borders or planters? Our free Soil Calculator works out how much topsoil or compost you need in cubic metres and litres — and how many bags to buy — from the size of the area you want to fill.
Loose soil settles by around 10–20% after watering, so ordering a touch extra is never a bad idea.
How to Use
- Measure the length and width of the bed or area in metres.
- Enter how deep you want the soil in centimetres.
- Enter the bag size sold by your supplier, in litres.
- Click Calculate soil to see the volume and bag count.
- For large areas, compare the bulk-bag figure — it is often cheaper.
Key Features
- Gives results in cubic metres, litres and bag counts.
- Compares bags against bulk bags for the best-value option.
- Works for topsoil, compost, mulch and bark.
- Instant results with clear metric measurements.
- Free to use with no sign-up, on any device.
FAQs
How deep should soil be in a raised bed?
Aim for 30 cm for vegetables and most flowers; salad leaves and herbs manage with 15–20 cm, while root vegetables appreciate 40 cm or more.
How many litres are in a cubic metre?
One cubic metre equals 1,000 litres. A typical 50-litre bag therefore covers 0.05 m³, so a 1 m³ bed needs 20 such bags.
Should I buy bags or a bulk bag?
For anything above roughly 0.5 m³, a bulk bag (around 0.7 m³) is usually cheaper per litre than individual bags — the calculator shows both figures so you can compare.
Does soil settle after filling?
Yes — loose soil settles by 10–20% after watering and a few weeks of weather. Fill beds slightly proud of the top and top up as needed.
Can I use this for compost or mulch?
Absolutely. The volume maths is identical for compost, well-rotted manure, mulch and decorative bark — just enter the depth of the layer you want.
Related Tools
You may also like our Volume Calculator, Concrete Calculator and Area Calculator.