Find out how much soil, compost, or mulch you need for garden beds. Get cubic feet, cubic yards, and bag counts.
0cu ft
| Item | Amount |
|---|---|
| Cubic yards | |
| 1 cu ft bags | |
| 1.5 cu ft bags | |
| 2 cu ft bags | |
| 3 cu ft bags |
Volume is length × width × depth, converted to cubic feet. The calculator adds your settling allowance and then shows the result as cubic yards and as bags in the common sizes.
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Once you need around 1 cubic yard or more, delivered bulk soil or mulch is usually cheaper than bags. Under that, bags are easier to haul and handle. Compare prices locally.
This assumes rectangular beds. For round or odd shapes, use the shape's area in place of length × width, or split it into rectangles.
A 4 x 8 foot bed filled 12 inches deep holds 32 cubic feet. With a 10 percent settling allowance, you need about 35 cubic feet, or roughly 18 bags of 2 cubic foot soil.
At a 3 inch depth, 100 square feet takes 25 cubic feet. Add 10 percent and you need about 27.5 cubic feet, roughly 14 bags of 2 cubic foot mulch.
A popular mix is about equal parts topsoil, compost, and a loosening material such as peat moss or coconut coir. Many garden centers also sell raised bed mixes that are already blended.
Ten to twelve inches suits most vegetables and flowers. Root crops like carrots and parsnips do better with 12 inches or more.
Not always. Some gardeners fill the bottom with logs, branches, or yard waste to save money, then top it with soil. This lowers the volume you need, so enter only the depth of soil you plan to buy.