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How Much Soil Do I Need for a Raised Garden Bed?

Calculate raised bed soil volume in cubic feet, cubic yards, and bag counts before you buy.

5 min read

The raised bed soil formula

Soil volume is length times width times depth. The common mistake is mixing inches and feet. If your bed depth is measured in inches, divide it by 12 before multiplying by the bed length and width.

Example: 8 by 4 by 10 inches

An 8 foot by 4 foot bed filled 10 inches deep needs about 26.7 cubic feet of soil. If each bag contains 1.5 cubic feet, that is about 18 bags before adding a small buffer for settling.

Bags versus bulk soil

Bagged soil is convenient for smaller beds and easier transport. Bulk soil can be more economical for larger projects, but delivery, access, and where the soil will be dumped can affect the real project cost.

Plan for settling

Fresh soil often settles after watering and planting. Buying a little extra helps you top up the bed without making a second trip, especially for deeper beds or new mixes with compost.

Planning checklist

Before you make the final plan

  • Measure the actual bed length, width, and depth before buying materials.
  • Compare bagged materials with bulk delivery if the project is larger than one small bed.
  • Plan for settling, drainage, compost, mulch, and access around the bed.
  • Use calculator results as a baseline, then adjust for plant type and local conditions.

Related calculators

Turn this guide into numbers.

Next step

Use the estimate before you buy materials.

Turn this guide into a quick planning number, then compare the result with local prices, supplier notes, and your real site conditions.