How Much Soil Does a 4x8 Raised Bed Need?

A 4 by 8 foot bed has 32 square feet of surface area. Soil volume depends on fill depth: area multiplied by depth in feet. Since depth is often measured in inches, divide inches by 12.

Worked example at 11 inches

32 square feet times 11 divided by 12 equals 29.33 cubic feet, or about 1.09 cubic yards before an allowance. If you add 10% for settling and handling, plan for about 32.27 cubic feet (1.20 cubic yards). At 1.5 cubic feet per bag, 32.27 divided by 1.5 rounds up to 22 bags.

Before you order

Measure the inside dimensions if the bed walls take up meaningful space. Consider whether you will fill the entire depth with soil or use an appropriate lower layer. Soil compacts, and beds can have tapered walls; this is a practical estimate rather than an exact fill specification.

Use the raised bed soil calculator for multiple beds or a different depth.