Raised Bed Soil Calculator
Find out exactly how much soil your raised bed needs, in cubic feet, cubic yards, and bags. Entirely in your browser.
Recommended mix
How it works
The calculator multiplies your bed's length, width, and depth to get its volume, then converts that to the units soil is actually sold in:
- Cubic feet. The unit on most bagged soil. A standard large bag holds 1.5 or 2 cubic feet.
- Cubic yards. The unit for bulk delivery. One cubic yard is 27 cubic feet.
- Bag counts. How many 0.75, 1.5, and 2 cubic foot bags you'd need, rounded up.
The recommended mix follows the common 60/30/10 formula for raised beds: 60% topsoil for structure, 30% compost for nutrients, and 10% aeration material such as perlite, coarse sand, or rice hulls. It's a guideline, not a law — beds grow fine on many mixes, and soil settles a few inches in the first season, so don't be alarmed when the level drops.
How deep should a raised bed be?
Most vegetables are happy with 10 to 12 inches of soil depth, especially if the bed sits on open ground the roots can continue into. Salad greens and herbs get by with as little as 6 inches. Deep-rooted crops like carrots, parsnips, and potatoes prefer 12 to 18 inches.
Filling a deep bed entirely with purchased soil gets expensive fast. If your bed is deeper than about 12 inches, you can fill the bottom with logs, branches, and leaves first — we wrote up exactly how in our guide to filling a raised bed without going broke.