YardRaised Bed Soil Calculator: Yards & Bags
This soil calculator for a raised bed estimates how much fill you need in cubic feet, yards and bags. Measure the inside of each bed and subtract existing soil to calculate the remaining volume.
01 Measure your space
Add each bed or section. Different sizes are welcome.
Extra is an ordering allowance, not a recommendation to apply a thicker layer.
Enable JavaScript for an interactive estimate. Formulas and examples are available below.
02 Compare your prices
OPTIONALReplace example prices with your store and supplier quotes.
Minimum and increment use the selected bulk pricing unit. Prices exclude tax and installation.
Take it to the store
Save a copy of your result here. It stays in this browser after you reload the page.
Measure the space still to be filled
Use the inside length and width of the bed, not the outside frame dimensions. Enter your target fill depth and the depth already occupied by existing soil. The calculator subtracts existing fill before calculating the new quantity. Do not subtract soil that you plan to remove.
For several beds of different sizes, add a separate area for each one. The optional compost percentage divides the new fill into two components; it does not add compost on top of the calculated volume. Prices compare ready-mixed fill only, not separately purchased ingredients. For compost spread over an existing bed or lawn, use the compost calculator.
Example: soil for a 4 × 8 raised bed
A 4 × 8 ft bed filled to 12 inches needs 32 cubic feet, or about 1.19 cubic yards, before allowance. That is 22 whole bags of 1.5 cubic feet. If the bed already contains 4 inches of soil, the remaining 8 inches need about 21.33 cubic feet, or 15 of those bags.
At a user-selected 25% compost share, a completely empty 32-cubic-foot bed would use 8 cubic feet of compost and 24 cubic feet of the other fill component. This is a calculation example, not a universal soil recipe.
Choose the mix for your bed
Soil condition and bed construction matter. Maryland Extension describes different filling approaches depending on whether you are working above existing soil or replacing poor material. Use local guidance and soil testing to choose a mix, rather than treating a fixed percentage as right for every garden.
Frequently asked questions
Does the calculator account for settling?
Only through the extra-material percentage you enter. It does not predict the settling of a particular mix. Ask your supplier how much additional material is appropriate.
Should the bag say cubic feet or pounds?
Volume is needed for this calculation. Bags labeled by weight require a product-specific density to convert to cubic feet.
Do I fill the bed to the top of the frame?
Enter your intended soil level. If you want space below the rim for watering or mulch, reduce the target depth accordingly.
How the estimate works
For each rectangular area, multiply length by width, then multiply by depth in feet. A square uses side length × side length. An oval uses length × width × π ÷ 4. A circle uses π × radius². Add the volumes of all areas, then apply the extra-material percentage once.
For raised beds, remaining depth is target fill depth minus existing fill, with a minimum of zero. The compost share divides the final new-fill volume rather than increasing it. There are 27 cubic feet in one cubic yard. Bag quantities round up to whole bags. Bulk orders round up to the increment you enter, after applying your supplier’s minimum order. Taxes, installation, pickup costs and additional fees are excluded.