Soil Calculator
Find out how much soil you need to fill raised garden beds. Enter the size and depth of a bed and how many beds you have, and see the soil in cubic yards, cubic feet, and bags.
Soil needed
1.19 cu yd
Check the highlighted fields to see your result.
- Bags
- 22
- Volume
- 32 cu ft
- Area covered
- 32 sq ft
Results are estimates for information only and do not constitute financial, medical, or legal advice.
How it works
The soil you need is the volume of the bed: length times width times the depth you want to fill. With several identical beds, multiply by the number of beds. Bagged soil is sold by the cubic foot, so the calculator also counts bags.
The formulas
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12 × beds
Cubic yards = cubic feet ÷ 27 · Bags = cubic feet ÷ bag size
Worked example
One raised bed is 8 × 4 ft, filled 12 inches deep, with soil in 1.5 cu ft bags.
- Volume: 8 × 4 × 12 ÷ 12 = 32 cubic feet, about 1.19 cubic yards.
- Bags: 32 ÷ 1.5 = 21.3, so buy 22 bags.
Frequently asked questions
How deep should soil be in a raised bed?
About 6 inches is enough for lettuce and herbs, 8 to 12 inches suits most vegetables, and 12 to 18 inches gives room for deep roots like tomatoes and carrots. A taller bed can be partly filled with coarser material at the bottom.
Should I buy soil in bags or in bulk?
Bags are convenient for one or two small beds. For larger projects, bulk soil sold by the cubic yard is usually much cheaper. One cubic yard is 27 cubic feet, or 18 bags of 1.5 cubic feet.
Why add a little extra?
New soil settles after watering, often by 10% to 20% in the first weeks. Many gardeners fill beds slightly above the rim or keep a few extra bags to top them up.