Raised Bed Soil & Planting Calculator
Raised Bed Soil Calculator
Calculate cubic feet, cubic yards, liters, bags, settling allowance, mix, and shopping list for raised beds.
How to use
- Enter the relevant bed, bag, bulk, mix, container, spacing, top-off, or depth inputs.
- Review soil volume, bags, cost, mix breakdown, warnings, and the shopping list.
- Copy the shopping list or print the result before buying materials.
Formula
length × width × effective depth × number of beds × (1 + settling allowance)
Example calculation
A 4 ft × 8 ft bed filled 12 in deep equals 32 ft³, or about 1.19 yd³.
Common sizes and presets
Includes 4×8 presets at 6, 8, 10, 12, 18, and 24 inches, common soil bag sizes, grow bag groups, and 4×4 / 4×8 square-foot grids.
Practical notes
- Default units use feet for length and width, inches for depth.
- Use freeboard when the soil surface should sit below the bed edge.
Shopping notes
Affiliate-safe placeholder for soil, compost, raised bed kits, grow bags, mulch, trellises, and garden tools. Add real affiliate links only after checking product relevance and disclosure requirements.
FAQ
How much soil do I need for a 4x8 raised bed?
A 4×8 bed filled 12 inches deep needs 32 cubic feet, or about 1.19 cubic yards, before any settling allowance.
How many bags of soil do I need for a raised bed?
Divide the required cubic feet by the bag volume in cubic feet, then round up. The calculator does this automatically.
Should I add extra soil for settling?
Many gardeners add 10–15% for initial settling, especially when compost-heavy material is used.
What is the difference between cubic feet and cubic yards?
One cubic yard is 27 cubic feet. Bulk soil is usually sold by the cubic yard; bags are often labeled in cubic feet, dry quarts, or liters.
Is 40 lb of soil the same as 40 quarts?
No. Pounds measure weight, while quarts measure volume. Soil weight changes with moisture and material density.
How deep should a raised bed be?
Six to eight inches can work for shallow greens and herbs. Tomatoes, peppers, squash, and longer root crops usually benefit from 12 inches or more.
Can I fill a raised bed with only topsoil?
This calculator can split ratios, but it does not prescribe a universal mix. Drainage, compost quality, local soil, and crop choice all matter.
Should I buy bagged soil or bulk soil?
For larger volumes, bulk may be cheaper. For smaller volumes, bagged soil is often simpler and avoids overbuying.
How much compost should I add to a raised bed?
Use the mix calculator to split the total volume by percentage. A 60/30/10 mix uses 30% compost by volume.
Can I use this calculator for raised beds on concrete?
Yes for volume planning, but drainage, bed depth, and material choice need extra care. This tool does not replace local gardening advice.
Why does the calculator warn about pounds and kilograms?
Weight-based bags are unreliable for volume because wet compost, dry potting mix, and topsoil can have very different densities.
Disclaimer
BedSoil results are planning estimates for buying and mixing soil. They are not agricultural, engineering, pest, disease, fertilizer, or crop-yield advice. Check product labels, local material quality, drainage, bed construction, climate, and crop variety before purchasing materials.