How much soil for a 1.2 × 2.4 m raised bed?

This is the metric equivalent of a 4 × 8 ft bed, and with a settling allowance it comes to just under one cubic metre (1,000 litres). A single bulk bag of topsoil or compost blend may cover most of it in one delivery instead of twenty small bags, but check the bag’s actual volume first.

What to know about a 1.2 × 2.4 m raised bed

Railway-style sleepers are a common way to build this size; new ones are often 2.4 m long and about 200 × 100 mm in section. One sleeper high gives roughly 20 cm of depth and two give roughly 40 cm. Sleepers are thick, though: with 100 mm timbers the inside of a bed measured 1.2 × 2.4 m on the outside is nearer 1.0 × 2.2 m, which holds about a quarter less soil. Measure inside the frame.

Bulk bags are sold under names like “1 tonne bag” or “builder’s bag”, but a bag of damp topsoil weighing a tonne usually holds less than a cubic metre. Ask the supplier for the volume in litres or m³ so you can compare it with the 871 litres here.

Most garden-centre compost and topsoil comes in 40–75 litre bags, and the bag count changes a lot across that range, so check the table below before you load the car.

The US-size version of this bed is How much soil for a 4×8 raised bed. Levelling a lawn area rather than filling a box? See How much topsoil for 50 m² at 10 cm.