How much soil for a 3x8 raised bed? Bags and cubic yards

Soil for a 3 × 8 ft bed at each depth

Whole bags are rounded up. The bed’s wall height is not the soil depth: measure the depth you plan to fill.

Bags of

Soil depth	Cubic feet	Cubic yards	Bags of ¾ ft³	Bags of 1 ft³	Bags of 1.5 ft³	Bags of 2 ft³	Bags of 3 ft³
6 in	12	0.44	16	12	8	6	4
8 in	16	0.59	22	16	11	8	6
10 in	20	0.74	27	20	14	10	7
12 in	24	0.89	32	24	16	12	8
18 in	36	1.33	48	36	24	18	12
24 in	48	1.78	64	48	32	24	16

Measure inside the walls

The table uses the full 3 × 8 ft. If that is the outside size of a wooden bed built from boards 1½ inches thick, the growing space inside is 33 × 93 inches. At 12 inches deep that holds 21.31 cubic feet, 11% less than the table. Metal and composite walls are thinner, but corner posts and braces still take space, so measure between the inner walls before you order.

Building it from 2 × 6 boards? The 3 × 8 ft bed plan has the cut list and the steps for this outside size: filled 10 inches deep, it takes 12 bags.

Beds sold at 3 × 8 ft

These are the beds we list in this size. A maker’s stated capacity often differs from the table because the inside is smaller than the advertised size or the maker assumes a different fill depth.

What to plant in a 3 × 8 ft bed

Four planting layouts drawn to scaleA 3 × 8 ft bed holds 24 heads of lettuce, 384 carrots or 4 trellised tomatoes at Colorado State University Extension’s spacings. See a salad bed, tomatoes and peppers, and roots and onions with every plant counted.

Work out your own bed

Open these measurements in the soil calculator to change the depth, add more beds or split the fill into a mix. To compare the cost of bags with a bulk delivery for 0.89 cubic yards, use the bagged vs bulk soil calculator.

Other bed sizes

2 ft wide

2 × 8 ft16 ft³ at 12 in

3 ft wide

4 ft wide

4 × 8 ft32 ft³ at 12 in

8 ft wide

8 × 8 ft64 ft³ at 12 in