Soil Calculator Formula

Understand the math behind the soil calculator. Each variable explained with a worked example.

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Formulas Used

Cubic Yards Needed

cubic_yards = volume_cuft / 27

Approximate Tons

tons = volume_cuft / 27 * 1.1

Bags (1 cu ft)

bags_1cuft = ceil(volume_cuft)

Variables

VariableDescriptionDefault
lengthLength(ft)12
widthWidth(ft)4
depthDepth(in)8
volume_cuftDerived value= length * width * depth / 12calculated

How It Works

Soil Volume Calculation

Volume (cu ft) = L × W × Depth(in) / 12

Cubic Yards = Volume / 27

Topsoil weighs approximately 1.1 tons per cubic yard.

Worked Example

12×4 ft raised bed, 8 inches deep.

length = 12width = 4depth = 8
  1. 01Volume = 12 × 4 × 8/12 = 32 cu ft
  2. 02Cubic yards = 32 / 27 = 1.2 yards
  3. 03Tons = 1.2 × 1.1 = 1.3 tons

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