How many bags of soil for a 4x8 raised bed?

24 bags of 1.5 cubic feet or 18 bags of 2 cubic feet for a 12 inch deep bed, including 10% for settling. At 8 inches: 16 and 12; at 18 inches: 36 and 27. Check the cubic feet on your bag; 1 and 1.5 cubic feet bags are common for raised bed mix, 2 for garden soil.

How many yards of soil for a 4x8 raised bed?

1.3 cubic yards at 12 inches deep with settling, 0.87 at 8 inches and 1.96 at 18 inches. Bulk soil is sold by the half yard or yard; for one bed order a yard and use the rest to top up later, or share a delivery with a neighbour.

How much soil for a 4x4 raised bed?

18 cubic feet (12 bags of 1.5 cubic feet, 0.65 cubic yards) at 12 inches, 12 cubic feet at 8 inches and 26 at 18. A 4 x 4 bed at 12 inches is about the largest job that still makes sense in bags.

How deep should a raised bed be?

8 inches is enough for salads, herbs and shallow-rooted vegetables if the soil below is open; 12 inches suits most vegetables and lets you fill without digging; 18 inches or more for root crops, on a hard base such as concrete or gravel, and for beds you want to work without bending. Deeper beds cost more soil than most people expect: 18 inches is half as much again as 12.

What should I fill a raised bed with?

A mix, not straight topsoil: about 60% screened topsoil, 30% compost and 10% something for drainage such as coarse sand or perlite is a common recipe, or a bagged raised bed mix. Deep beds can have the bottom third filled with logs, branches and rough compost (hugelkultur), which cuts the soil by a third; the table figure is the total volume, so buy soil for the top two thirds.

How much does the soil for a raised bed weigh?

Topsoil is about 1 US tons per cubic yard dry, so the 1.3 yards in a 4 x 8 bed at 12 inches is roughly 1.3 tons, more when wet. On a deck or a rooftop, use a lightweight mix and check what the structure carries.

How much soil for a 4x8 raised bed? (3x6, 4x4, 4x12 too)

A 4 x 8 ft raised bed filled 12 inches deep holds 32 cubic feet of soil; with 10% for settling you buy 35 cubic feet, which is 1.3 cubic yards, 24 bags of 1.5 cubic feet or 18 bags of 2 cubic feet. At 8 inches deep it is 16 bags of 1.5, at 18 inches 36. A cubic yard is 18 of the 1.5 cubic feet bags, so a single 4 x 8 bed is already the size where bulk soil is cheaper. The tables cover 2 x 8 to 4 x 12 ft beds at 8, 12 and 18 inches.

Open the gravel calculator

Soil by bed size and depth

Inside dimensions of the frame, filled to the depth shown, plus 10% because new soil settles after the first watering. Bags are the common 1.5 and 2 cubic feet sizes; check yours, 1 cubic foot bags are also sold and a 40 lb bag of topsoil is under 1 cubic foot.

8 inches deep, 10% for settling
Bed	Cubic feet	Cubic yards	Bags (1.5 cu ft)	Bags (2 cu ft)	US tons
2 x 8 ft	12	0.43	8	6	0.4
3 x 6 ft	13	0.49	9	7	0.5
4 x 4 ft	12	0.43	8	6	0.4
4 x 8 ft	23	0.87	16	12	0.9
4 x 12 ft	35	1.3	24	18	1.3

12 inches deep, 10% for settling
Bed	Cubic feet	Cubic yards	Bags (1.5 cu ft)	Bags (2 cu ft)	US tons
2 x 8 ft	18	0.65	12	9	0.7
3 x 6 ft	20	0.73	14	10	0.7
4 x 4 ft	18	0.65	12	9	0.7
4 x 8 ft	35	1.3	24	18	1.3
4 x 12 ft	53	1.96	36	27	2

18 inches deep, 10% for settling
Bed	Cubic feet	Cubic yards	Bags (1.5 cu ft)	Bags (2 cu ft)	US tons
2 x 8 ft	26	0.98	18	14	1
3 x 6 ft	30	1.1	20	15	1.1
4 x 4 ft	26	0.98	18	14	1
4 x 8 ft	53	1.96	36	27	2
4 x 12 ft	79	2.93	53	40	3

How the numbers are worked out

Length x width x depth in feet: 4 x 8 x 1 = 32 cubic feet, 35 with settling. Divide by 27 for cubic yards or by the bag size for bags, round up. The soil and gravel calculator does it for any bed; measure the inside of the frame, not the outside, since 2-inch boards take an inch off each side.

Bags or bulk?

One 4 x 4 bed at 8 or 12 inches: bags, about 8 to 12 of them. One 4 x 8 bed at 12 inches or anything more: bulk, because 24 bags is a pickup-load of plastic and a yard delivered usually costs less. Bulk soil should be screened topsoil or a garden blend, never fill; ask what is in it, and mix in compost either way.

Metric: beds in litres and 50 L bags

Inside dimensions, 10% for settling
Bed	Depth	Litres	Bags (50 L)	Tonnes
1.2 x 1.2 m	20 cm	317	7	0.38
1.2 x 2.4 m	20 cm	634	13	0.76
1 x 3 m	20 cm	660	14	0.79
1.2 x 1.2 m	30 cm	475	10	0.57
1.2 x 2.4 m	30 cm	950	20	1.14
1 x 3 m	30 cm	990	20	1.19
1.2 x 1.2 m	45 cm	713	15	0.86
1.2 x 2.4 m	45 cm	1,426	29	1.71
1 x 3 m	45 cm	1,485	30	1.78

Before you fill it

On soil, line the bottom with cardboard to kill grass and let roots through; on concrete, a layer of gravel and a fabric, and a deeper bed.
Fill in layers and water each one; the bed drops an inch or two the first week, which is what the 10% covers. Keep two bags back to top it up.
Mulch on top (2 inches) keeps the moisture in: the mulch guide has it by area. Topsoil for a lawn or a border is in the topsoil guide.

Frequently asked questions

How many bags of soil for a 4x8 raised bed?: 24 bags of 1.5 cubic feet or 18 bags of 2 cubic feet for a 12 inch deep bed, including 10% for settling. At 8 inches: 16 and 12; at 18 inches: 36 and 27. Check the cubic feet on your bag; 1 and 1.5 cubic feet bags are common for raised bed mix, 2 for garden soil.
How many yards of soil for a 4x8 raised bed?: 1.3 cubic yards at 12 inches deep with settling, 0.87 at 8 inches and 1.96 at 18 inches. Bulk soil is sold by the half yard or yard; for one bed order a yard and use the rest to top up later, or share a delivery with a neighbour.
How much soil for a 4x4 raised bed?: 18 cubic feet (12 bags of 1.5 cubic feet, 0.65 cubic yards) at 12 inches, 12 cubic feet at 8 inches and 26 at 18. A 4 x 4 bed at 12 inches is about the largest job that still makes sense in bags.
How deep should a raised bed be?: 8 inches is enough for salads, herbs and shallow-rooted vegetables if the soil below is open; 12 inches suits most vegetables and lets you fill without digging; 18 inches or more for root crops, on a hard base such as concrete or gravel, and for beds you want to work without bending. Deeper beds cost more soil than most people expect: 18 inches is half as much again as 12.
What should I fill a raised bed with?: A mix, not straight topsoil: about 60% screened topsoil, 30% compost and 10% something for drainage such as coarse sand or perlite is a common recipe, or a bagged raised bed mix. Deep beds can have the bottom third filled with logs, branches and rough compost (hugelkultur), which cuts the soil by a third; the table figure is the total volume, so buy soil for the top two thirds.
How much does the soil for a raised bed weigh?: Topsoil is about 1 US tons per cubic yard dry, so the 1.3 yards in a 4 x 8 bed at 12 inches is roughly 1.3 tons, more when wet. On a deck or a rooftop, use a lightweight mix and check what the structure carries.

How much gravel do I need for a driveway?
Cubic metres, tonnes and bulk bags of gravel for typical driveway sizes at 50, 75 and 100 mm depth, with the imperial equivalents in cubic yards and tons.
How much does a cubic yard of gravel weigh?
A cubic yard of gravel weighs about 1.2 to 1.4 US tons; sand and topsoil differ. Pounds and tons per yard, yards per ton, and tonnes per cubic metre for each material.
How much gravel for a shed base? 6x8 to 12x16 ft
Cubic yards, tons and bags of gravel for 6x8, 8x10, 10x12 and 12x16 ft shed bases at 4 and 6 inches, why the base runs past the shed, and metric sizes in tonnes.
How much sand and gravel do I need under pavers?
Gravel base at 4 or 6 inches and 1 inch of bedding sand for 100 to 500 sq ft of pavers: cubic yards, tons and bags, plus the metric patio in tonnes and bulk bags.

Last updated 2026-09-12. Figures are planning estimates from typical product data: check the yield, size or coverage printed on what you buy and round up.