PlantAlongFree calculator
Raised bed soil calculator
How much soil your beds hold, how many bags that is, and how to split it into a mix an extension service recommends.
You need
- Cubic feet
- 26.7
- Cubic yards
- 0.99
- Litres
- 755
- Bags
- 14of 2 cubic feet
Shop the essentials
What you'll need
Once you know how much soil you need: what to fill and build the bed with.
Fill the bedRaised bed soilBagged soil for filling beds. Compare each bag’s volume with your result.: check price on Amazon (opens in a new tab)
Fill the bedBagged compostCompost to mix into a new bed.: check price on Amazon (opens in a new tab)
Build the bedRaised bed kit, 4 × 8 ftA ready-to-assemble bed frame.: check price on Amazon (opens in a new tab)
Move the soilGarden cart or wheelbarrowFor moving bags and soil to the bed.: check price on Amazon (opens in a new tab)
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How the numbers are worked out
Volume is length × width × depth for each bed, times the number of beds, converted to feet. The example above is one 8 × 4 ft bed, 10 in deep: 8 × 4 × (10 ÷ 12) = 26.7 cubic feet.
Conversions use exact factors: 1 cubic yard = 27 cubic feet, and 1 cubic foot = 28.316846592 litres3. Bags are rounded up.
Check the bag. Bag sizes differ by product. Compressed bales (peat, coir) are labelled with their compressed volume, so a bale fills more than its label says, by an amount the label may not state4. The calculator treats every bag as loose fill. Soil also settles after watering, which these numbers do not include.
Depth
Sources
Every number on this page points here. Links open the original publication.
- University of Maryland Extension, Home and Garden Information Center (Maryland Grows blog)Filling your raised bed
- Iowa State University Extension and Outreach, Yard and GardenWhat would be a good soil mix for a raised bed?
- National Institute of Standards and TechnologyNIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement
- National Institute of Standards and Technology (as adopted by the National Conference on Weights and Measures)NIST Handbook 130 (2026), Section IV.B: Uniform Regulation for the Method of Sale of Commodities
- Colorado State University ExtensionVegetable Planting Guide (CMG GardenNotes #720)