Raised bed soil: example for 120 × 80 cm

How much soil a raised bed needs depends on its area and fill height. Here is a worked example and a round bed for comparison.

Example: rectangular raised bed

Inner size 120 × 80 cm, inner height 60 cm, 5 cm watering margin. The fill height is 55 cm. Volume: 120 × 80 × 55 cm = 528 liters. With 15% allowance for settling that is 607 liters (0.61 m³).

Branches and coarse shrub cuttings (30%): 182 liters
Leaves, turf, grass clippings (20%): 121 liters
Compost and soil mix (25%): 152 liters
Potting soil (25%): 152 liters

Usually you only buy compost and soil: about 304 liters, which is 8 bags of 40 liters.

Example: round raised bed

Diameter 100 cm, inner height 50 cm, 5 cm margin. The area is about 7,854 cm², the fill height 45 cm, which is about 353 liters and 406 liters with allowance. You need to buy about 6 bags of 40 liters.

Typical mistakes

Measuring the outer instead of the inner size: the boards take up space.
No allowance for settling: the bed sinks in the first year.
Filling the whole height with bought soil: branches and leaves at the bottom save money.

The values are planning guides, not gardening advice.

Go to the calculator

General planning aid, not gardening advice. Actual amounts depend on material, moisture and compaction. Updated: November 2026

Frequently asked questions

How much soil do I need for a 120 × 80 cm raised bed?

With 60 cm inner height and a 5 cm margin, about 607 liters including 15% allowance, of which around 300 liters of compost and soil to buy. Enter your own size in the calculator.

Do I have to fill the whole raised bed with soil?

Not necessarily. Layering is common: coarse cuttings at the bottom, leaves and grass clippings above, compost and potting soil on top. That way you buy less soil.