Boneyard Tools

Raised Bed Soil Calculator

Estimate the soil to fill a raised garden bed. Enter the bed length and width in feet and the depth in inches to see cubic feet, cubic yards and bags.

How to estimate raised bed soil

  1. Enter the inside length and width of the bed in feet.
  2. Enter the fill depth in inches and how many beds you have.
  3. Read off the cubic feet, cubic yards and bag count.

Examples

8 by 4 ft bed, 12 inches deep

L 8, W 4, depth 12 in, 1 bed
32 cu ft, 1.1852 cu yd, 22 bags at 1.5 cu ft

Frequently asked questions

How deep should a raised bed be?

Most vegetables thrive in 10 to 12 inches of soil, since that depth gives roots room and holds moisture. Deep-rooted crops like carrots or tomatoes prefer the full 12 inches or more.

How many cubic feet are in a cubic yard?

There are 27 cubic feet in a cubic yard. Bulk soil is usually sold by the cubic yard, so the calculator converts your cubic feet for ordering in bulk.

What soil mix should I use?

A common raised bed mix is roughly one third compost, one third topsoil and one third aeration such as coarse sand or perlite. Adjust to suit your plants and local soil.

Should I fill the bed to the very top?

Leave an inch or two below the rim so water and mulch do not spill over. Soil also settles after watering, so plan to top up a little in the first season.

Why round bags up?

Soil is sold by the whole bag, so partial needs round up. A little extra is handy for topping up after the soil settles or for nearby pots.

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