Raised bed volume

The amount of soil a raised bed holds, found by multiplying length × width × depth. A 4 × 8 foot bed 12 inches deep holds 32 cubic feet.

Also called: raised bed soil, how much soil for a raised bed

Use the depth you'll actually fill, not the height of the walls.

The formula

Volume in cubic feet = length × width × depth, with all three in feet. Divide by 27 for cubic yards.

For a 4 × 8 foot bed filled 12 inches deep: 4 × 8 × 1 = 32 cubic feet, which is 1.19 cubic yards or 16 bags of 2 cubic feet.

Fill depth, not wall height

Use the depth you will actually fill. The same 4 × 8 bed filled to 10 inches holds 4 × 8 × (10 ÷ 12) = 26.7 cubic feet, a little under one cubic yard.

In metric

Multiply metres × metres × metres for cubic metres, then × 1,000 for litres. A bed 1.2 m × 2.4 m filled 30 cm deep holds 1.2 × 2.4 × 0.3 = 0.864 m³, or 864 litres.

Where this comes from

Iowa State University Extension and Outreach, How to Determine the Amount of Mulch Needed for a Garden Bed, checked 2026-10-28
Everyday Measure, rectangular-bed geometry, checked 2026-10-28

Tools that use this

Everyday Measure · everydaymeasure.com/glossary/raised-bed-volume/